Image processing apparatus and method

ABSTRACT

The present disclosure relates to an image processing device and a method capable of suppressing the reduction of an image quality due to encoding/decoding. The image processing device includes: a quantization unit that when orthogonal transform processing is skipped with respect to a current block, quantizes all components of the current block using one weighting coefficient and when the orthogonal transform processing is performed on the current block, quantizes each component of the current block using a quantization matrix; an encoding unit that encodes the coefficient of the current block which is quantized by the quantization unit; and a transmission unit that transmits the coded data of the current block which is obtained by being encoded by the encoding unit. The present disclosure can be applied to, for example, an image processing device.

TECHNICAL FIELD

The present disclosure relates to an image processing device and method,and more particularly relates to an image processing device and methodcapable of suppressing image deterioration.

BACKGROUND ART

In recent years, devices have come into widely use in which an image issubjected to compression encoding by employing a coding system byhandling image information as digital, and at this time compressing theimage by orthogonal transform, such as discrete cosine transform or thelike, and motion compensation, taking advantage of redundancy which is afeature of the image information, in order to perform highly efficienttransmission and storage of information. Examples of this coding systeminclude a Moving Picture Experts Group (MPEG) and so forth.

In particular, MPEG2 (ISO/IEC 13818-2) is defined as a general-purposeimage coding system, and is a standard that covers both interlacedscanning images and progressive scanning images as well asstandard-resolution images and high-definition images. For example, theMPEG2 is currently widely used in a wide range of applications forprofessional use and for consumer use. With use of the MPEG2 compressionmethod, in the case of a standard-resolution interlaced scanning imagehaving, for example, 720×480 pixels, an amount of encode (bit rate) of 4to 8 Mbps is allocated. In addition, with use of the MPEG-2 compressionmethod, in the case of a high-resolution interlaced scanning imagehaving, for example, 1920×1088 pixels, an amount of encode (bit rate) of18 to 22 Mbps is allocated. Owing to this, it is possible to realize ahigh compression rate and favorable image quality.

The MPEG2 has been mainly used for high image quality encoding suitablefor broadcasting, but has not been compatible with coding systems of anamount of encode (bit rate) lower than that of MPEG1, in other words, ahigher compression rate. With the widespread use of mobile terminals, itis expected that the demand for such a coding system will increase inthe future, and in response to this, standardization of a MPEG4 codingsystem has been performed. With regard to an image coding system, thespecification thereof was approved as an international standard asISO/IEC 14496-2 in December 1998.

Further, in recent years, standardization of a standard called H.26L(ITU-T (International Telecommunication Union TelecommunicationStandardization Sector) Q6/16 VCEG (Video Coding Expert Group)) hasprogressed, the object of which was initially image encoding forvideoconferencing usage. With H.26L, it has been known that thoughgreater computation amount is requested for encoding and decodingthereof as compared to a conventional coding system such as MPEG2 orMPEG4, higher encoding efficiency is realized. Also, currently, as partof activity of MPEG4, standardization including a function that is notsupported by H.26L with this H.26L taken as base to realize higherencoding efficiency has been performed as Joint Model ofEnhanced-Compression Video Coding.

As a standardization schedule, an international standard called H.264and MPEG-4 Part 10 (Advanced Video Coding, hereinafter referred to asAVC) was established in March 2003.

Furthermore, as an extension of the H.264/AVC, standardization of FRExt(Fidelity Range Extension), including encoding tools necessary forbusiness use, such as RGB, 4:2:2, or 4:4:4, as well as 8×8 DCT andquantization matrices defined in MPEG-2, was completed in February 2005.Accordingly, a coding system capable of favorably expressing even filmnoise included in movies, using H.264/AVC, has been established, whichis used for a wide range of applications such as Blu-Ray Discs(registered trademark).

However, there have recently been growing needs for encoding at a highercompression rate, for example, needs for compressing an image havingabout 4000×2000 pixels, which is four times that of a high-vision image,or for distributing high-vision images in an environment with a limitedtransmission capacity, such as the Internet. Therefore, in a VideoCoding Expert Group (VCEG) under ITU-T, which is described above,studies for improving encoding efficiency have been continuouslyperformed.

Therefore, for the purpose of further improving an encoding efficiencycompared with the AVC, standardization of a coding system called HighEfficiency Video Coding (HEVC) is currently being conducted by JointCollaboration Team-Video Coding (JCTVC), which is a jointstandardization team of ITU-T and ISO/IEC (see, for example, Non-PatentDocument 1).

However, in the HEVC standard disclosed in Non-Patent Document 1, atechnique called “Intra Transform Skipping” is employed (see, forexample, Non-Patent Document 2).

That is, first, a flag relating whether Transform Skip (referred also toas an “orthogonal transform skip”) is applicable in the sequence, istransmitted to a Sequence Parameter Set (SPS).

When the value is 1, it is possible to apply the TransformSkip to 4×4luminance and chrominance orthogonal transform blocks.

A flag relating on/off of the TransformSkip is transmitted to eachblock.

With respect to the block to which the TransformSkip is applied, thereis no change in entropy encoding, quantization, loop filter processingor the like.

CITATION LIST Non-Patent Document

-   Non-Patent Document 1: Benjamin Bross, Woo-Jin Han, Jens-Rainer Ohm,    Gary J. Sullivan, Thomas Wiegand, “Working Draft 4 of    High-Efficiency Video Coding”, JCTVC-F803_d2, Joint Collaborative    Team on Video Coding (JCT-VC) of ITU-T SG16 WP3 and ISO/IEC    JTC1/SC29/WG11 6th Meeting: Torino, IT, 14-22 Jul. 2011-   Non-Patent Document 2: Cuiling Lan, Jizheng Xu, Gary J. Sullivan,    Feng Wu, “Intra transform skipping”, JCTVC-I0408, Joint    Collaborative Team on Video Coding (JCT-VC) of ITU-T SG 16 WP 3 and    ISO/IEC JTC 1/SC 29/WG 119th Meeting: Geneva, CH, 27 Apr.-7 May 2012

SUMMARY OF THE INVENTION Problems to be Solved by the Invention

However, a coefficient of a block to which a TransformSkip is applied isa value relating to a spatial domain, a coefficient of a block to whichthe TransformSkip is not applied is a value relating to a frequencydomain, and thus both characteristics are different from each other.

For this reason, when an encoding process is performed on both of theblock to which the TransformSkip is applied and the block to which theTransformSkip is not applied without taking the difference in thesecharacteristics into consideration, there is a concern that encodingefficiency is deteriorated.

The present disclosure is developed in consideration of such a situationand can suppress the reduction of image quality due to encoding/decodingprocesses.

Solutions to Problems

According to an aspect of the present disclosure, there is provided animage processing device including:

a quantization unit that uses a weighting coefficient applied to anorthogonal transform skip block in which orthogonal transform processingis skipped and quantizes the orthogonal transform skip block; and

an encoding unit that encodes a coefficient of the orthogonal transformskip block quantized by the quantization unit.

The quantization unit may use the one weighting coefficient.

The quantization unit may quantize an orthogonal transform skip blockhaving a block size of 4×4 using the weighting coefficient.

The image processing device may further include a transmission unit thattransmits skip enable information indicating whether or not to enablethe skip of the orthogonal transform processing as a picture parameterset.

The transmission unit may further transmit the weighting coefficient.

The quantization unit may quantize a non-orthogonal transform skip blockin which orthogonal transform processing is performed, using aquantization matrix different from a weighting coefficient matrixobtained by performing matrix processing on the weighting coefficient.

The image processing device may further include a transmission unit thatmodulates coded data obtained by performing quantization by thequantization unit and encoding by the encoding unit image data totransmit the coded data as a transmission signal.

The image processing device may further include a multiplexer thatmultiplexes coded data obtained by performing quantization by thequantization unit and encoding by the encoding unit image data, withaudio coded data.

The image processing device may further include an imaging unit thatcaptures an image of an object to generate image data, wherein thequantization unit quantizes the orthogonal transform skip block of theimage data obtained by imaging with the imaging unit.

The image processing device may further include an audio codec unit thatperforms encoding and decoding on audio data.

The image processing device may further include a recording unit thatrecords coded data obtained by performing quantization by thequantization unit and encoding by the encoding unit image data, on astorage medium

According to an aspect of the present disclosure, an image processingmethod including: using a weighting coefficient applied to an orthogonaltransform skip block in which orthogonal transform processing is skippedto quantize the orthogonal transform skip block; and encoding acoefficient of the quantized orthogonal transform skip block.

In the another aspect of the present disclosure, the orthogonaltransform skip block is quantized using a weighting coefficient appliedto an orthogonal transform skip block in which orthogonal transformprocessing is skipped, and a coefficient of the quantized orthogonaltransform skip block is encoded.

Further, the image processing device described above may be anindependent device or may be an internal block constituting one imageencoding device.

Effects of the Invention

According to the present disclosure, it is possible to encode an image.In particularly, it is possible to suppress the reduction of imagequality due to encoding/decoding.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a block diagram illustrating an example of a mainconfiguration of an image encoding device.

FIG. 2 is a diagram for describing an example of a configuration of acoding unit.

FIG. 3 is a diagram illustrating an example of a quantization matrixtransmission.

FIG. 4 is a diagram illustrating an example of a sequence parameter set.

FIG. 5 is a diagram illustrating an example of the sequence parameterset which follows FIG. 4.

FIG. 6 is a diagram illustrating an example of a picture parameter set.

FIG. 7 is a diagram illustrating an example of the picture parameter setwhich follows FIG. 6.

FIG. 8 is a diagram for describing an example of a condition ofquantization.

FIG. 9 is a diagram illustrating an example of a sequence parameter set.

FIG. 10 is a diagram illustrating an example of the sequence parameterset which follows FIG. 9.

FIG. 11 is a diagram illustrating an example of a picture parameter set.

FIG. 12 is a diagram illustrating an example of the picture parameterset which follows FIG. 11.

FIG. 13 is a block diagram illustrating an example of a mainconfiguration of an orthogonal transform skip or the like.

FIG. 14 is a flowchart for describing an example of a flow of anencoding process.

FIG. 15 is a flowchart for describing an example of a flow of orthogonaltransform skip control processing.

FIG. 16 is a flowchart for describing an example of a flow of orthogonaltransform processing.

FIG. 17 is a flowchart for describing an example of a flow ofquantization processing.

FIG. 18 is a flowchart for describing an example of a flow of deblockingfilter processing.

FIG. 19 is a block diagram illustrating an example of a mainconfiguration of an image decoding device.

FIG. 20 is a block diagram illustrating an example of a mainconfiguration of an inverse orthogonal transform skip unit or the like.

FIG. 21 is a flowchart for describing an example of a flow of a decodingprocess.

FIG. 22 is a flowchart for describing an example of a flow of inversequantization processing.

FIG. 23 is a flowchart for describing an example of a flow of inverseorthogonal transform processing.

FIG. 24 is a diagram illustrating another example of a sequenceparameter set.

FIG. 25 is a diagram illustrating an example of a picture parameter set.

FIG. 26 is a flowchart for describing an example of a flow of skipenable information generation processing.

FIG. 27 is a flowchart for describing an example of a flow of skipenable information reception processing.

FIG. 28 is a diagram illustrating an example of a multiple viewpointimage coding system.

FIG. 29 is a diagram illustrating an example of a main configuration ofa multiple viewpoint image encoding device to which the presenttechnology is applied.

FIG. 30 is a diagram illustrating an example of a main configuration ofa multiple viewpoint image decoding device to which the presenttechnology is applied.

FIG. 31 is a diagram illustrating an example of a hierarchical imagecoding system.

FIG. 32 is a diagram illustrating an example of a main configuration ofa hierarchical image encoding device to which the present technology isapplied.

FIG. 33 a diagram illustrating an example of a main configuration of ahierarchical image decoding device to which the present technology isapplied.

FIG. 34 is a block diagram illustrating an example of a mainconfiguration of a computer.

FIG. 35 is a block diagram illustrating an example a schematicconfiguration of a television apparatus.

FIG. 36 is a block diagram illustrating an example of a schematicconfiguration of a mobile phone.

FIG. 37 is a block diagram illustrating an example of a schematicconfiguration of a recording and reproducing device.

FIG. 38 is a block diagram illustrating an example of a schematicconfiguration of an imaging device.

FIG. 39 is a block diagram illustrating an example of scalable encodingutilization.

FIG. 40 is a block diagram illustrating another example of the scalableencoding utilization.

FIG. 41 is a block diagram illustrating further another example of thescalable encoding utilization.

FIG. 42 is a block diagram illustrating an example of a schematicconfiguration of a video set.

FIG. 43 is a block diagram illustrating an example of a schematicconfiguration of a video processor.

FIG. 44 is a block diagram illustrating another example of a schematicconfiguration of the video processor.

MODE FOR CARRYING OUT THE INVENTION

Hereinafter, modes for carrying out the present disclosure (hereinafter,referred to as embodiments) will be described. Further, the descriptionis given in the following order.

1. First embodiment (Image encoding device)

2. Second embodiment (Image decoding device)

3. Third embodiment (Transmission control of skip enable information)

4. Fourth embodiment (Multiple viewpoint image encoding/Multipleviewpoint image decoding device)

5. Fifth embodiment (Hierarchical image encoding/Hierarchical imagedecoding device)

6. Sixth embodiment (Computer)

7. Seventh embodiment (Application example)

8. Eighth embodiment (Application example of scalable encoding)

9. Ninth embodiment (Set/Unit/Module/Processor)

1. First Embodiment

[Image Encoding Device]

FIG. 1 is a block diagram illustrating an example of a mainconfiguration of an image encoding device.

An image encoding device 100 illustrated in FIG. 1 encodes image datausing prediction processing of, for example, high efficiency videocoding (HEVC) or a system that is compliant therewith.

As illustrated in FIG. 1, the image encoding device 100 includes an A/Dconverter 101, a screen rearrangement buffer 102, a computation unit103, an orthogonal transform unit 104, a quantization unit 105, alossless encoding unit 106, an accumulation buffer 107, an inversequantization unit 108, and an inverse orthogonal transform unit 109. Inaddition, the image encoding device 100 includes a computation unit 110,a deblocking filter 111, a frame memory 112, a selection unit 113, anintra prediction unit 114, a motion prediction/compensation unit 115, apredicted image selection unit 116, and a rate control unit 117.

The image encoding device 100 further includes an orthogonal transformskip unit 121.

The A/D converter 101 performs A/D conversion on input image data,supplies the image data (digital data) obtained by the conversion to thescreen rearrangement buffer 102, and stores the image data therein. Thescreen rearrangement buffer 102 rearranges the frame images stored indisplay order into order of frames for encoding according to a group ofpicture (GOP) structure and supplies the image, in which order of theframes has been rearranged, to the computation unit 103. In addition,the screen rearrangement buffer 102 supplies the image, in which theorder of the frames has been rearranged, to the intra prediction unit114 and the motion prediction/compensation unit 115.

The computation unit 103 subtracts a predicted image supplied from theintra prediction unit 114 or the motion prediction/compensation unit 115through the predicted image selection unit 116 from the image read fromthe screen rearrangement buffer 102 and outputs difference informationto the orthogonal transform unit 104. For example, in a case of theimage to which intra encoding is performed, the computation unit 103subtracts, from the image read from the screen rearrangement buffer 102,the predicted image supplied from the intra prediction unit 114.Further, in a case of the image to which inter encoding is performed,for example, the computation unit 103 subtracts, from the image readfrom the screen rearrangement buffer 102, the predicted image suppliedfrom the motion prediction/compensation unit 115.

The orthogonal transform unit 104 performs an orthogonal transform suchas a discrete cosine transform and a Karhunen-Loeve transform on thedifference information supplied from the computation unit 103 andsupplies a transform coefficient thereof to the quantization unit 105.

The quantization unit 105 quantizes the transform coefficient suppliedfrom the orthogonal transform unit 104. The quantization unit 105 sets aquantization parameter based on information on a target value of anencode amount supplied from the rate control unit 117 and performsquantization thereof. The quantization unit 105 supplies the quantizedtransform coefficient to the lossless encoding unit 106.

The lossless encoding unit 106 encodes the transform coefficient, whichis quantized by the quantization unit 105, using any coding system.Since coefficient data is quantized under control of the rate controlunit 117, the encode amount thereof is the target value set by the ratecontrol unit 117 (or approximates the target value).

In addition, the lossless encoding unit 106 acquires informationindicating a mode of intra prediction and the like from the intraprediction unit 114 and acquires information indicating a mode of interprediction or difference motion vector information from the motionprediction/compensation unit 115.

The lossless encoding unit 106 encodes these various information piecesaccording to a coding system, to contain (multiplex) the variousinformation pieces as part of header information of coded data (referredalso to as a coded stream). The lossless encoding unit 106 supplies thecoded data obtained by the encoding to the accumulation buffer 107 andaccumulates the coded data therein.

For example, the coding system of the lossless encoding unit 106includes variable-length encoding or computation encoding. For example,the variable-length encoding includes Context-Adaptive Variable LengthCoding (CAVLC) and the like defined by the H.264/AVC system. Forexample, the computation encoding includes Context-Adaptive BinaryArithmetic Coding (CABAC) and the like.

The accumulation buffer 107 temporarily holds the coded data suppliedfrom the lossless encoding unit 106. The accumulation buffer 107 outputsthe held coded data to, for example, a recording device (recodingmedium) or a transmission path not illustrated in the latter part atpredetermined timing. That is, the accumulation buffer 107 is also atransmission unit for transmitting the coded data.

The quantized transform coefficient by the quantization unit 105 is alsosupplied to the inverse quantization unit 108. The inverse quantizationunit 108 inversely quantizes the quantized transform coefficient by amethod corresponding to the quantization by the quantization unit 105.The inverse quantization unit 108 supplies the obtained transformcoefficient to the inverse orthogonal transform unit 109.

The inverse orthogonal transform unit 109 performs inverse orthogonaltransform on the transform coefficient supplied from the inversequantization unit 108 by a method corresponding to orthogonal transformprocessing by the orthogonal transform unit 104. An output obtained bythe inverse orthogonal transform processing (restored differenceinformation) is supplied to the computation unit 110.

The computation unit 110 adds an predicted image supplied from the intraprediction unit 114 or the motion prediction/compensation unit 115through the predicted image selection unit 116 to the restoreddifference information which is a result of the inverse orthogonaltransform processing supplied from the inverse orthogonal transform unit109, thereby obtaining a locally decoded image (decoded image). Thedecoded image is supplied to the deblocking filter 111 or the framememory 112.

The deblocking filter 111 appropriately performs deblocking filterprocessing on the decoded image supplied from the computation unit 110.For example, the deblocking filter 111 performs the deblocking filterprocessing on the decoded image to remove block distortion of thedecoded image.

The deblocking filter 111 supplies a result of the filter processing(decoded image after filter processing) to the frame memory 112.Further, as described above, the decoded image output from thecomputation unit 110 can be supplied to the frame memory 112 withoutpassing through the deblocking filter 111. That is, it is possible toomit the filter processing by the deblocking filter 111.

The frame memory 112 stores the decoded image to be supplied andsupplies the stored decoded image as a reference image to the selectionunit 113 at predetermined timing.

The selection unit 113 selects a supply destination of the referenceimage supplied from the frame memory 112. For example, in the case ofthe inter prediction, the selection unit 113 supplies the referenceimage supplied from the frame memory 112 to the motionprediction/compensation unit 115.

The intra prediction unit 114 performs an intra prediction (in-screenprediction) to generate the predicted image using a pixel value within acurrent picture which is the reference image supplied from the framememory 112 through the selection unit 113. The intra prediction unit 114performs the intra prediction in a plurality of intra prediction modesprepared in advance.

The intra prediction unit 114 generates the predicted image in all ofthe intra prediction modes to be candidates and evaluates a costfunction value of each predicted image using the input image suppliedfrom the screen rearrangement buffer 102 to select an optimal mode. Uponselecting the optimal intra prediction mode, the intra prediction unit114 supplies the generated predicted image to the predicted imageselection unit 116 in the optimal mode.

In addition, as described above, the intra prediction unit 114appropriately supplies intra prediction mode information indicating anadopted intra prediction mode to the lossless encoding unit 106 toencode the supplied intra prediction mode information.

The motion prediction/compensation unit 115 performs motion prediction(inter prediction) using the input image supplied from the screenrearrangement buffer 102 and the reference image supplied from the framememory 112 through the selection unit 113. The motionprediction/compensation unit 115 performs motion compensation processingaccording to a detected motion vector and generates the predicted image(inter predicted image information). The motion prediction/compensationunit 115 performs such an inter prediction in the plurality of interprediction modes prepared in advance.

The motion prediction/compensation unit 115 generates the predictedimage in all of the inter prediction modes to be candidates. The motionprediction/compensation unit 115 evaluates the cost function value ofeach predicted image using the input image supplied from the screenrearrangement buffer 102 and the information of the generated differencemotion vector to select an optimal mode. Upon selecting the optimalinter prediction mode, the motion prediction/compensation unit 115supplies the generated predicted image in the optimal mode to thepredicted image selection unit 116.

The motion prediction/compensation unit 115 supplies the informationindicating an adopted inter prediction mode, information required forperforming the processing in the inter prediction mode at the time ofdecoding the coded data and the like to the lossless encoding unit 106and encodes the supplied information. For example, the requiredinformation may include information of the generated difference motionvector, a flag indicating the index of a prediction motion vector asprediction motion vector information, and the like.

The predicted image selection unit 116 selects a supply source of thepredicted image to be supplied to the computation unit 103 or thecomputation unit 110. For example, in the case of intra encoding, thepredicted image selection unit 116 selects intra prediction unit 114 asthe supply source of the predicted image and supplies the predictedimage to be supplied from the intra prediction unit 114 to thecomputation unit 103 or the computation unit 110. In addition, forexample, in the case of inter encoding, the predicted image selectionunit 116 selects the motion prediction/compensation unit 115 as thesupply source of the predicted image and supplies the predicted image tobe supplied from the motion prediction/compensation unit 115 to thecomputation unit 103 or the computation unit 110.

Based on an encode amount of the coded data accumulated in theaccumulation buffer 107, the rate control unit 117 controls a rate ofquantization operation of the quantization unit 105 such that overflowor underflow does not occur.

The orthogonal transform skip unit 121 controls execution of theorthogonal transform processing in the orthogonal transform unit 104. Inaddition, according to the control, the orthogonal transform skip unit121 controls quantization processing by the quantization unit 105,inverse quantization processing by the inverse quantization unit 108,inverse orthogonal transform processing by the inverse orthogonaltransform unit 109, and deblocking filter processing by the deblockingfilter 111. Further, the orthogonal transform skip unit 121 suppliesinformation necessary on a skip of the orthogonal transform processingand information on the quantization or the deblocking filter to thelossless encoding unit 106 and transmits the supplied information to adecoding side from the accumulation buffer 107.

[Coding Unit]

In an AVC system, a hierarchical structure including a macroblock and asub macroblock is specified. However, a macroblock of 16 pixels×16pixels is not most suitable for a large image frame, such as an ultrahigh definition (UHD; 4000 pixels×2000 pixels), that will be the subjectof a next-generation coding system.

Thus, for example, a coding unit (CU) is specified in an HEVC system asillustrated in FIG. 2.

The CU is also called a coding tree block (CTB), and is a partial regionof an image in a picture unit, which serves the similar role as themacroblock in the AVC system. The latter has a fixed size of 16×16pixels, whereas the size of the former is not fixed and is thusspecified in image compression information in each sequence.

For example, the maximum size (Largest Coding Unit (LCU)) and theminimum size (Smallest Coding Unit (SCU)) of the CU are specified in asequence parameter set (Sequence Parameter Set (SPS)) included in thecoded data to be output.

Each LCU can be further divided into a smaller CU by settingsplit_flag=1 within the range not falling below the size of the SCU. Inan example illustrated in FIG. 2, the LCU is 128×128 pixels in sizewhile the maximum hierarchical depth becomes 5. The CU having the sizeof 2N×2N pixels is divided into CUs having the size of N×N pixels thatis one level lower in the hierarchy when the value of split_flag is “1”.

Further, the CU is divided into a prediction unit (PU) that is a region(a partial region of an image in a picture unit) to be a processing unitfor the intra prediction or the inter prediction and is also into atransform unit (TU) that is a region (a partial region of an image in apicture unit) to be a processing unit for the orthogonal transform.Currently, the HEVC system can perform 16×16 and 32×32 orthogonaltransforms in addition to 4×4 and 8×8 orthogonal transforms.

As in the above HEVC system, in the case of a coding system in which theCU is defined and various types of processing are performed with the CUas a unit, it is considered that the macroblock in the AVC systemcorresponds to the LCU and a block (sub-block) corresponds to the CU. Inaddition, it is considered that a motion compensation block in the AVCsystem corresponds to the PU. However, since the CU has a hierarchicalstructure, the size of the LCU in the uppermost level thereof isgenerally set larger than the macroblock in the AVC system, for example,128×128 pixels.

Therefore, hereinafter, it is assumed that the LCU also includes themacroblock in the AVC system and the CU also includes the block(sub-block) in the AVC system. That is, the “block” used in thefollowing description indicates any partial region within the picture,and is not limited in the size, shape, characteristics of the block andthe like. In order words, any region (processing unit), for example, TU,PU, SCU, CU, LCU, sub-block, macroblock, or slice is included in the“block”. Naturally, partial regions (processing units) other than theseregions are also included therein. The description is appropriatelygiven in the case of limiting the size or the processing unit asnecessary.

Next, basic technical elements related to the present technology will bedescribed.

[Quantization Matrix]

As in the AVC, the quantization of an orthogonal transform coefficientis performed for every orthogonal transform processing unit in the HEVC.A quantization matrix is used for the quantization, but the quantizationmatrix is prepared for every size of the orthogonal transform processingunit. However, for example, when a large quantization matrix such as16×16 matrix or 32×32 matrix is transmitted, there is a concern thatencoding efficiency is reduced.

Here, as illustrated in FIG. 3, the large quantization matrix (orquantization matrix larger than a predetermined size) for example, 16×16matrix or 32×32 matrix is transmitted in a size of 8×8 and is upsampledby a zero-order hold to be applied to each orthogonal transform size.Further, a DC component is separately transmitted to a matrix to whichupsample is applied.

In HEVC, as illustrated in FIGS. 4 to 7, information on the quantizationmatrix (Scaling List) is transmitted to a sequence parameter set (SPS)or a picture parameter set (PPS). FIGS. 4 and 5 are diagramsillustrating examples of the sequence parameter set. FIGS. 6 and 7 arediagrams illustrating examples of the picture parameter set.

[Deblocking Filter]

As in the AVC, the deblocking filter is defined in a motion compensationloop in the HEVC. The deblocking filter performs filter processing forreducing block distortion occurring in block boundaries.

That is, in the deblocking filter processing, the block boundaries aredetected, a type or an strength of the filter, an offset and the likeare decided based on quantization parameters or the like at the blockboundaries, thereby performing the filter processing.

[Mode Selection]

However, it is important to select an appropriate prediction mode inorder to achieve higher encoding efficiency in the AVC and HEVC codingsystems.

As an example of the selection method, a method which is implemented inthe reference software called a joint model (JM)) of H.264/MPEG-4/AVC(which is available at http://iphome.hhi.de/suehring/tml/index.htm) canbe used.

The JM software enables a mode decision method to be selected from twomodes of High Complexity Mode and Low Complexity Mode which will bedescribed below. In any modes, a cost function value for everyprediction mode ‘Mode’ is calculated, and a prediction mode whichminimizes the cost function value is selected as an optimal mode for theblock or the macroblock.

In the High Complexity Mode, the cost function is expressed by thefollowing expression (1).

Cost(Mode εΩ)=D+λ*R  (1)

Here, “Ω” represents a universal set of candidate modes for encoding theblock or the macroblock and “D” represents energy difference between adecoded image and an input image when the encoding is performed in theprediction mode. “λ” represents a Lagrange multiplier given as afunction of a quantization parameter. “R” represents a total encodeamount including the orthogonal transformation coefficient when theencoding is performed in the mode.

That is, in order to perform encoding in the High Complexity Mode, alarger computation amount is required because a temporary encodingprocessing needs to be performed once in all candidate modes tocalculate the parameters D and R.

In the Low Complexity Mode, the cost function is expressed by thefollowing expression (2).

Cost(Mode εΩ)=D+QP2Quant(QP)*HeaderBit  (2)

Here, “D” represents energy difference between a predicted image and aninput image and is different from the High Complexity Mode. “QP2Quant(QP)” is given as a function of a quantization parameter QP, and“HeaderBit” is an encode amount related to information which belongs toa Header such as a motion vector or a mode, not including the orthogonaltransform coefficient.

That is, in the Low Complexity Mode, although it is necessary to performa prediction process for the respective candidate modes, since it is notnecessary to obtain a decoded image, it is not necessary to perform theencoding process. Thus, the low complexity mode can be realized withlower computation amount than the High Complexity Mode.

[Orthogonal Transform Skip]

Incidentally, a technique of “Intra Transform Skipping” proposed inNon-Patent Document 2 is employed in an HEVC standard. An orthogonaltransform skip (Transform Skip) is a technique of omitting (skipping)orthogonal transform processing.

Generally, the orthogonal transform processing is performed on imagedata (differential image data) for every block to convert spatial domaininformation in the block into frequency domain information, therebyallowing coefficients in the block to be concentrated on a lowerfrequency, and thus it is possible to increase a bias. Thus, theencoding efficiency is improved.

However, it may be also considered that there is a case where such abias is less likely to occur according to designs in the block. Forexample, a gradation or a strong edge easily occurs in artificial imagessuch as CG images or captions, compared to natural images. For thisreason, a high-frequency component easily occurs, and the bias isunlikely to occur even when the orthogonal transform processing isperformed. Therefore, by allowing for the skipping of the orthogonaltransform processing in such a block, it is possible to further improvethe encoding efficiency.

Further, the skipping of the orthogonal transform processing is referredto as an orthogonal transform skip (Transform Skip) in the followingdescription, and a block to which the orthogonal transform skip(Transform Skip) is applied is also referred to as an orthogonaltransform skip block. In addition, a block to which the orthogonaltransform skip is not applied (orthogonal transform is performed) isalso referred to as a non-orthogonal transform skip block.

In this technique, first, a flag indicating whether the orthogonaltransform skip (Transform Skip) can be applied in the sequence istransmitted to the sequence parameter set (SPS).

A flag (transform_skip_enabled_flag), which is skip enable informationindicating whether or not to enable/disable the orthogonal transformskip (TransformSkip), is transmitted to the sequence parameter set(SPS), as illustrated in FIG. 5.

This skip enable information (transform_skip_enabled_flag) is set by,for example, a user or the like. When this value is 1, the orthogonaltransform skip (TransformSkip) can be applied to 4×4 luminanceorthogonal transform blocks or 4×4 chrominance orthogonal transformblocks.

Then, on/off of the orthogonal transform skip (TransformSkip) isdetermined for every block, and a flag about the on/off thereof istransmitted.

[Encoding Efficiency]

Regardless of such skip control of the orthogonal transform, an entropyencoding process, quantization processing, loop filter processing andthe like are uniformly performed. That is, as on the non-orthogonaltransform skip block, the entropy encoding process, the quantizationprocessing, the loop filter processing and the like are also performedon the orthogonal transform skip block.

However, the quantization matrix is a weighting coefficient regardingthe frequency domain. That is, the quantization matrix is designed to beapplied to an orthogonal transform coefficient block. Accordingly, whensuch a quantization matrix is applied to a block having a spatial domainvalue (differential image data), the encoding efficiency may be reduced.That is, image quality may be deteriorated.

In addition, as described above, the orthogonal transform skip isapplied to an image in which the high-frequency component tends toappear. Therefore, there is a high possibility that the content of animage on the orthogonal transform skip block are largely different fromthose on the non-orthogonal transform skip block. That is, the blockdistortion easily occurs at the boundary between the orthogonaltransform skip block and the non-orthogonal transform skip block.

Therefore, as on other boundaries, when the deblocking filter processingis performed on the boundary between the orthogonal transform skip blockand the non-orthogonal transform skip block, the encoding efficiency maybe reduced. That is, the image quality may be deteriorated.

[Control According to Orthogonal Transform Skip]

Thus, according to whether a current block is the orthogonal transformskip (TransformSkip) block, the encoding process is controlled. Morespecifically, the quantization processing (inverse quantizationprocessing) of the encoding process and the deblocking processing arecontrolled.

[Control of Quantization Processing]

For example, in the case of the quantization processing, thequantization processing is performed on the non-orthogonal transformskip block in which the orthogonal transform is performed using aquantization matrix, and the quantization processing is performed on theorthogonal transform skip block in which the orthogonal transform isskipped using one weighting coefficient instead of the quantizationmatrix. That is, all coefficients of the orthogonal transform skip blockserving as the current block are quantized using the one weightingcoefficient.

A condition thereof is illustrated in FIG. 8. For example, asillustrated in FIG. 8, the quantization is performed on thenon-orthogonal transform skip block (orthogonal transform coefficientmatrix) using quantization matrix as in the prior art.

On the other hand, the 4×4 orthogonal transform skip block (matrix ofpre-orthogonal transform differential value) is quantized using aweighting coefficient matrix which is obtained by the quantization ofthe one weighting coefficient. Naturally, an actual computation methodis arbitrary, but basically performs a computation equivalent to thatusing the weighting coefficient matrix.

The weighting coefficient is arbitrary. For example, the weightingcoefficient may include a scalar value. For example, the DC component ofthe quantization matrix may be the weighting coefficient. Thequantization matrix is a weighting coefficient regarding the frequencydomain, but the DC component is a value regarding the frequency domainand is also a value regarding the spatial domain. If only the DCcomponent of the quantization matrix having these characteristics ispresent, it is unlikely to lead to reduction of the encoding efficiencyeven when the quantization is applied to each coefficient of theorthogonal transform skip block which is the value regarding the spatialdomain.

In this case, as illustrated in FIG. 8, DC components are extracted fromthe quantization matrix, and the weighting coefficient matrix isgenerated by rearranging the extracted DC components in 4×4, therebyquantizing the 4×4 orthogonal transform skip block (matrix ofpre-orthogonal transform differential value) using the weightingcoefficient matrix.

Further, for example, apart from the quantization matrix, the weightingcoefficient may be arbitrarily generated. A method of generating theweighting coefficient is arbitrary. Even in this case, as illustrated inFIG. 8, the weighting coefficient matrix is generated by rearranging theweighting coefficient in 4×4, thereby quantizing the 4×4 orthogonaltransform skip block (matrix of pre-orthogonal transform differentialvalue) using the weighting coefficient matrix. In this manner, forexample, only a portion to which the orthogonal transform skip block isapplied (for example, CG image) can be easily controlled to improve theimage quality or the like using the weighting coefficient independent ofthe quantization matrix, as compared to another portion.

Further, in this case, the weighting coefficient may be calculated inthe same manner such that a value on a coding side is the same as thaton a decoding side and may be transmitted to the decoding side from thecoding side.

In the case of transmitting the weighting coefficient, when a value ofthe skip enable information (transform_skip_enabled_flag) is a value(for example, 1) which enables the orthogonal transform skip, a scalarquantization value (weighting coefficient) applied to the orthogonaltransform skip block is transferred. For this reason, the sequenceparameter set and the picture parameter set described with reference toFIGS. 4 to 7 are changed as follows.

As a first change, the skip enable information(transform_skip_enabled_flag) is transmitted earlier than a quantizationmatrix (scaling list).

As a second change, skip enable information(transform_skip_enabled_flag) is also transmitted to the PPS so that theSPS is independent of the PPS in terms of parsing.

That is, the SPS is configured as illustrated in FIGS. 9 and 10, and thePPS is configured as illustrated in FIGS. 11 and 12.

Further, the weighting coefficient may be generated by a computation ofan average value or the like using, for example, the DC component of thequantization matrix which is applied to the quantization of a peripheralblock located at the periphery of the current block. Such a computationmethod is arbitrary and may be other than an average.

Even in this case, as illustrated in FIG. 8, the weighting coefficientmatrix is generated by rearranging the weighting coefficient in 4×4,thereby quantizing the 4×4 orthogonal transform skip block (matrix ofpre-orthogonal transform differential value) using the weightingcoefficient matrix. In this manner, the weighting coefficient iscalculated using the quantization matrix of the peripheral block, andthus it is also possible to easily calculate the weighting coefficienton the decoding side in the same manner as on the coding side. That is,the transmission of the weighting coefficient can be omitted, and theencoding efficiency can be improved by that rate.

[Control of Deblocking Filter]

Next, control of the deblocking filter will be described. In order forthe orthogonal transform skip (TransformSkip) to improve the encodingefficiency of an area including the CG images or captions, it isconsidered that the block distortion is likely to occur at the boundarybetween the orthogonal transform skip block and the non-orthogonaltransform skip block.

Thus, a detection whether the orthogonal transform skip block and thenon-orthogonal transform skip block come in contact with each otheracross the block boundary is performed, and the strength adjustment ofthe deblocking filter is performed on the boundary between theorthogonal transform skip block and the non-orthogonal transform skipblock in the following manner to make deblocking filtering easilyperformed.

For example, when the deblocking filter processing is applied to theboundary between the orthogonal transform skip block and thenon-orthogonal transform skip block, a value of boundary strength (bs)acting as block-boundary strength is set to be “+1”. By increasing thebs value in this manner, the control is made so as to apply strongerfiltering. That is, a stronger deblocking filter can be applied to theboundary between the orthogonal transform skip block and thenon-orthogonal transform skip block. Further, instead of setting the bsvalue to +1, the bs value may be fixed to a large value of, for example,2 and the like.

In addition, for example, adjustment of the filter strength is performedfrom parameters such as the bs value, α, and β, but a strong filter maybe applied to the boundary between the orthogonal transform skip blockand the non-orthogonal transform skip block regardless of the controlresult of such a filter strength. Thus, it is possible to apply moredirectly a strong deblocking filter to the boundary between theorthogonal transform skip block and the non-orthogonal transform skipblock.

Further, for example, the boundary between the orthogonal transform skipblock and the non-orthogonal transform skip block may be set as asmaller offset compared to the β and tc. Thus, it is possible to easilyapply the deblocking filter to the boundary between the orthogonaltransform skip block and the non-orthogonal transform skip block.

By applying the strength adjustment of the deblocking filter asdescribed above, it is possible to more easily apply the deblockingfilter to the boundary between the orthogonal transform skip block andthe non-orthogonal transform skip block and to improve the efficiency ofimage compression information to be output.

Further, plural methods of applying the deblocking filter are consideredas described above, and it may be used in combination with the pluralmethods. Naturally, methods other than those described above may beincluded in such methods.

[Example of Configuration of Orthogonal Transform Skip or the Like]

FIG. 13 is a block diagram illustrating an example of a mainconfiguration of the orthogonal transform skip unit 121 and the like.

As illustrated in FIG. 12, the orthogonal transform skip unit 121 isconfigured to include a skip encoding unit 131 and a skip determinationunit 132.

The skip encoding unit 131 acquires the orthogonal transform coefficientand the pre-orthogonal transform differential value of the current blockfrom the orthogonal transform unit 104 when the current block is 4×4block. The skip encoding unit 131 performs the encoding process in thecase where the orthogonal transform skip is not applied, using thesupplied orthogonal transform coefficient, and generates a cost functionvalue thereof. In addition, the skip encoding unit 131 performs theencoding process in the case where the orthogonal transform skip isapplied, using the supplied pre-orthogonal transform differential valueand generates a cost function value thereof. The skip encoding unit 131supplies the cost function values to the skip determination unit 132.

Further, when the current block is larger than the 4×4 block, the skipencoding unit 131 omits such processing. In this case, the skipdetermination unit 132 supplies a control signal which issues aninstruction for performing the orthogonal transform, to the orthogonaltransform unit 104. The orthogonal transform unit 104 performs theorthogonal transform of the current block based on the control.

The skip determination unit 132 acquires the skip enable information(transform_skip_enabled_flag) indicating whether or not to enable theskip of the orthogonal transform processing, from the lossless encodingunit 106. This skip enable information (transform_skip_enabled_flag) isset in advance by, for example, a user or the like and is stored in thelossless encoding unit 106. The skip determination unit 132 supplies acontrol signal for instructing whether or not to enable the orthogonaltransform skip corresponding to the skip enable information(transform_skip_enabled_flag) to the orthogonal transform unit 104.

For example, when the skip enable information(transform_skip_enabled_flag) indicates that the orthogonal transformskip (for example, the value is 1) is enabled, the skip determinationunit 132 supplies the control signal for enabling the orthogonaltransform skip to the orthogonal transform unit 104. In addition, whenthe skip enable information (transform_skip_enabled_flag) indicates thatthe orthogonal transform skip (for example, the value is 0) is disabled,the skip determination unit 132 supplies the control signal forprohibiting the orthogonal transform skip to the orthogonal transformunit 104.

In addition, the skip determination unit 132 determines an optimal modebased on the cost function values supplied from the skip encoding unit131. That is, it is determined whether or not to apply the orthogonaltransform skip (TransformSkip) to the current block. The skipdetermination unit 132 supplies the determined result (informationindicating the determined optimal mode) as the control signal to theorthogonal transform unit 104, the quantization unit 105, the deblockingfilter 111, the inverse quantization unit 108, and the inverseorthogonal transform unit 109.

In addition, the skip determination unit 132 generates skipidentification information (TransformSkipFlag) for identifying thedetermined result (whether the orthogonal transform skip is applied tothe current block) and supplies and transmits the skip identificationinformation to the lossless encoding unit 106.

With respect to the pre-orthogonal transform differential value acquiredfrom the computation unit 103, the orthogonal transform unit 104generates the orthogonal transform coefficient and the pre-orthogonaltransform differential value of the current block which are not disabledby the control signal supplied from the skip encoding unit 131 in allmodes. The orthogonal transform unit 104 supplies the generated theorthogonal transform coefficient and the pre-orthogonal transformdifferential value of the current block to the skip encoding unit 131.Further, when the orthogonal transform skip is disabled by the controlsignal, the orthogonal transform unit 104 supplies only the orthogonaltransform coefficient of the current block to the skip encoding unit131.

As described above, when a mode is determined in the orthogonaltransform skip unit 121, the orthogonal transform unit 104 acquires thecontrol signal supplied from the skip determination unit 132 andperforms processing of the designated mode according to the control.That is, the orthogonal transform unit 104 executes or skips theorthogonal transform processing. In case of executing, the orthogonaltransform unit supplies the orthogonal transform coefficient to thequantization unit 105 and in the case of skipping, the pre-orthogonaltransform differential value to the quantization unit 105.

In this manner, the orthogonal transform unit 104 can appropriatelyperform the orthogonal transform as necessary to suppress the reductionof the encoding efficiency, and thus it is possible to suppress thedeterioration of the image quality due to encoding/decoding.

Further, the orthogonal transform unit 104 holds the orthogonaltransform coefficient and the pre-orthogonal transform differentialvalue of the current block in all modes to be supplied to the skipencoding unit 131 and, from among the coefficients and values, mayselect an orthogonal transform coefficient and a pre-orthogonaltransform differential value in a mode according to the control signalsupplied from the skip determination unit 132 to supply it thequantization unit 105. Thus, it is possible to omit the processing andreduce a load.

As illustrated in FIG. 13, the quantization unit 105 is configured toinclude a quantization matrix setting unit 141, a weighting coefficientgeneration unit 142, and a quantization processing unit 143.

The quantization matrix setting unit 141 supplies the quantizationmatrix, which is set by the user or the like, to the weightingcoefficient generation unit 142.

The weighting coefficient generation unit 142 acquires the controlsignal supplied from the skip determination unit 132. The weightingcoefficient generation unit 142 supplies the quantization matrix or theweighting coefficient to the quantization processing unit 143 based onthe control of the control signal.

For example, when the orthogonal transform skip is not applied, theweighting coefficient generation unit 142 supplies the quantizationmatrix, which is supplied from the quantization matrix setting unit 141in the mode designated by the control signal, to the quantizationprocessing unit 143.

In addition, for example, when the orthogonal transform skip is applied,the weighting coefficient generation unit 142 generates the weightingcoefficient and supplies the generated weighting coefficient to thequantization processing unit 143. As described above, a method ofgenerating the weighting coefficient is arbitrary. For example, a DCcomponent extracted from the quantization matrix supplied from thequantization matrix setting unit 141 may be set as the weightingcoefficient, apart from the quantization matrix supplied from thequantization matrix setting unit 141, another weighting coefficient maybe set, and the weighting coefficient may be calculated from the DCcomponent of the quantization matrix of the peripheral block.

The quantization processing unit 143 quantizes the orthogonal transformcoefficient or the pre-orthogonal transform differential value suppliedfrom the orthogonal transform unit 104 using the quantization matrix orthe weighting coefficient supplied from the weighting coefficientgeneration unit 142 and the quantization parameter or the like suppliedfrom the rate control unit 117.

That is, the quantization processing unit 143 quantizes the orthogonaltransform coefficient of the current block using the quantizationmatrix, the quantization parameter or the like when the orthogonaltransform coefficient is supplied from the orthogonal transform unit104. In addition, the quantization processing unit 143 quantizes thepre-orthogonal transform differential value of the current block usingthe weighting coefficient, the quantization parameter or the like whenthe pre-orthogonal transform differential value is supplied from theorthogonal transform unit 104.

The quantization processing unit 143 supplies the quantized coefficientto the lossless encoding unit 106 and the inverse quantization unit 108.In addition, the quantization processing unit 143 supplies and transmitsa parameter regarding the quantization of, for example, the weightingcoefficient or the like to the lossless encoding unit 106, whennecessary.

Thus, the quantization processing unit 143 can appropriately perform thequantization so as to suppress the deterioration of the image quality.Accordingly, the image encoding device 100 can suppress thedeterioration of the image quality due to the encoding/decoding. Inother words, the image encoding device 100 can improve the encodingefficiency.

Further, the quantization processing unit 143 may supply thequantization matrix or the weighting coefficient applied to thequantization processing together with, for example, the quantizedcoefficient to the inverse quantization unit 108.

Further, since a processing unit similar to the inverse quantizationunit 108 and the inverse orthogonal transform unit 109 is also formed inan image decoding device to be described below, the description thereofis also applied to the inverse quantization unit 108 and the inverseorthogonal transform unit 109, and thus the detailed description of theinverse quantization unit 108 and the inverse orthogonal transform unit109 will be not presented.

As illustrated in FIG. 13, the deblocking filter 111 is configured toinclude a boundary determination unit 151, a strength adjustment unit152, and a filtering unit 153.

The boundary determination unit 151 acquires the control signal suppliedfrom the skip determination unit 132, with respect to the current block.Further, the boundary determination unit 151 acquires skipidentification information (TransformSkipFlag) for identifying whetherthe orthogonal transform skip is applied to the peripheral block of thecurrent block (TransformSkipFlag). The boundary determination unit 151determines whether a current block boundary is the boundary between theorthogonal transform skip block and the non-orthogonal transform skipblock, based on such information, and supplies a control signalindicating the determined result to the strength adjustment unit 152.

The strength adjustment unit 152 generates various parameters such as Bsvalue, α, β, and tc and determines strength of the deblocking filterbased on these values and the control signal supplied from the boundarydetermination unit 151. That is, the strength adjustment unit 152determines the strength of the deblocking filter based on values ofvarious parameters such as the generated Bs value, α, β, and tc when thecurrent block boundary is not the boundary between the orthogonaltransform skip block and the non-orthogonal transform skip block. Inaddition, when the current block boundary is the boundary between theorthogonal transform skip block and the non-orthogonal transform skipblock, the strength adjustment unit 152 further makes filter strengthstrong based on the control signal in any manner as described above, forexample.

In this manner, the strength adjustment unit 152 notifies the filteringunit 153 of the set filter strength.

The filtering unit 153 performs the deblocking filter processing on apre-deblocking filter pixel value of the block boundary supplied fromthe computation unit 110 with the filter strength supplied from thestrength adjustment unit 152. The filtering unit 153 supplies apost-deblocking filter pixel value to the frame memory 112 to store ittherein. This information is used intra or inter prediction processing.

Thus, the deblocking filter 111 can perform the filter processing on theboundary between the orthogonal transform skip block and thenon-orthogonal transform skip block such that the stronger deblockingfilter is applied. Accordingly, the deterioration of the image qualityis further suppressed. That is, the image encoding device 100 cansuppress the deterioration of the image quality due to theencoding/decoding. In other words, the image encoding device 100 canimprove the encoding efficiency.

[Flow of Encoding Process]

Next, a flow of individual processing operations to be executed by theimage encoding device 100 as described above will be described. First,an example of a flow of an encoding process will be described withreference to a flowchart of FIG. 14.

In step S101, the lossless encoding unit 106 generates the skip enableinformation (transform_skip_enabled_flag) indicating whether or not toenable the skip of the orthogonal transform processing, based on theuser's instruction or the like, for example. For example, the skipenable information (transform_skip_enabled_flag) is transmitted to theSPS.

In step S102, the A/D converter 101 performs A/D conversion on an inputimage. In step S103, the screen rearrangement buffer 102 stores theimage obtained by the A/D conversion and rearranges respective picturesfrom a display order to an encoding order. In step S104, the intraprediction unit 114 performs intra prediction processing in the intraprediction mode.

In step S105, the motion prediction/compensation unit 115 performs intermotion prediction processing, in which the motion prediction or themotion compensation is performed in the inter prediction mode.

In step S106, the predicted image selection unit 116 determines anoptimal mode based on each of the cost function values output from theintra prediction unit 114 and the motion prediction/compensation unit115. That is, the predicted image selection unit 116 selects either oneof a predicted image generated by the intra prediction unit 114 and apredicted image generated by the motion prediction/compensation unit115.

In step S107, the computation unit 103 computes a difference between therearranged image obtained by the processing in step S103 and thepredicted image selected by the processing in step S106. The differencedata is reduced in the data amount as compared to original image data.Accordingly, the data amount can be compressed as compared to a case inwhich images are directly encoded.

In step S108, the orthogonal transform skip unit 121 performs orthogonaltransform skip control processing.

In step S109, the orthogonal transform unit 104 performs orthogonaltransform processing on the difference information generated by theprocessing in step S107 according to the processing result in step S108.

In step S110, the quantization unit 105 quantizes the orthogonaltransform coefficient or the pre-orthogonal transform differential valueobtained by the processing in step S109, using the quantizationparameter supplied from the rate control unit 117, according to theprocessing result in step S108.

The difference information quantized by the processing in step S110 islocally decoded as follows. That is, in step S111, the inversequantization unit 108 performs inverse quantization on the quantizedcoefficient (also referred to as a quantization coefficient) generatedby the processing in step S111 with characteristics corresponding tothose of the quantization unit 105, according to the processing resultin step S108. In step S112, the inverse orthogonal transform unit 109performs inverse orthogonal transform on the orthogonal transformcoefficient or the pre-orthogonal transform differential value obtainedby the processing in step S111 according to the processing result instep S108.

Since the description of each processing operation in step S111 and stepS112 corresponds to that of a similar processing operation to beexecuted in the decoding process, the detailed description thereof willbe not presented.

In step S113, the computation unit 110 adds the predicted image to thelocally decoded difference information to generate a locally decodedimage (an image corresponding to that input to the computation unit103).

In step S114, the deblocking filter 111 appropriately performs thedeblocking filter processing on the locally decoded image obtained bythe processing in step S113, according to the processing result in stepS108.

In step S115, the frame memory 112 stores the decoded image subjected tothe deblocking filter processing by the processing in step S114.Further, images that are not subjected to the filtering by thedeblocking filter 111 are also supplied from the computation unit 110and stored in the frame memory 112.

In step S116, the lossless encoding unit 106 encodes the quantizedcoefficient by the processing in step S110. That is, lossless encodingsuch as variable-length encoding or computation encoding is performed ondata corresponding to the difference image.

In addition, at this time, the lossless encoding unit 106 encodesinformation on a prediction mode of the predicted image selected by theprocessing in step S106 and adds the encoded information to the codeddata obtained by encoding the difference image. That is, the losslessencoding unit 106 also encodes information such as optimal intraprediction mode information supplied from the intra prediction unit 114or information according to the optimal inter prediction mode suppliedfrom the motion prediction/compensation unit 115 and adds the encodedinformation to the coded data.

Further, the lossless encoding unit 106 appropriately further encodesinformation on the orthogonal transform or the quantization and theencoded information to the coded data.

In step S117, the accumulation buffer 107 accumulates the coded dataobtained by the processing in step S116. The coded data accumulated inthe accumulation buffer 107 is appropriately read out and transmitted toa decoding side through a transmission path or a recording medium.

In step S118, the rate control unit 117 controls the rate ofquantization operation of the quantization unit 105 so as not to causeoverflow or underflow based on the encode amount (generated encodeamount) of the coded data accumulated in the accumulation buffer 107 bythe processing in step S117. In addition, the rate control unit 117supplies information on the quantization parameter to the quantizationunit 105.

The encoding process is completed when the processing in step S118 isended.

[Flow of Orthogonal Transform Skip Control Processing]

Next, an example of a flow of the orthogonal transform skip controlprocessing to be executed in step S108 of FIG. 14 will be described withreference to a flowchart of FIG. 15.

When the orthogonal transform skip control processing is started, theskip determination unit 132 determines in step S131 whether or not toenable a TransformSkip mode in which the orthogonal transform skip isperformed, based on the skip enable information(transform_skip_enabled_flag).

When it is determined that the TransformSkip mode is enabled, theprocessing proceeds to step S132. In step S132, the skip determinationunit 132 allows the TransformSkip mode to be included in a candidatemode. When the processing in step S132 is ended, the processing proceedsto step S134.

Further, when it is determined in step S132 that the TransformSkip modeis not enabled, the processing proceeds to step S133. In step S133, theskip determination unit 132 eliminates the TransformSkip mode from thecandidate mode. When the processing in step S133 is ended, theprocessing proceeds to step S134.

In step S134, the skip encoding unit 131 selects an unprocessedcandidate mode. In step S135, the skip encoding unit 131 determineswhether the selected mode is the orthogonal transform (TransformSkip)mode.

When it is determined to be the orthogonal transform (TransformSkip)mode, the processing proceeds to step S136. In step S136, the skipencoding unit 131 generates a weighting coefficient. When the processingin step S136 is ended, the processing proceeds to step S139.

When it is determined that the selected mode is not the orthogonaltransform (TransformSkip) mode in step S135, the processing proceeds tostep S137. In step S137, the skip encoding unit 131 performs theorthogonal transform on the current block.

In step S138, the skip encoding unit 131 acquires a quantization matrix.

In step S139, the skip encoding unit 131 performs an encoding operationusing the orthogonal transform coefficient obtained by the orthogonaltransform unit 104 or the pre-orthogonal transform differential valueand generates a cost function value with respect to the current mode.

In step S140, the skip encoding unit 131 determines whether all of thecandidate modes are processed. When an unprocessed candidate modeexists, the processing returns to step S134 and subsequent processingoperations are repeatedly executed. That is, each processing operationin step S134 to step S140 is repeatedly executed until the cost functionvalue is generated with respect to all of the modes.

When it is determined in step S140 that all of the candidate modes areprocessed, the processing proceeds to step S141. In step S141, the skipdetermination unit 132 determines the optimal mode based on the costfunction value.

In step S142, the skip determination unit 132 generates skipidentification information (TransformSkipFlag) based on the optimalmode.

When the processing in step S142 is ended, the orthogonal transform skipcontrol processing is completed, and the processing returns to theprocessing operation illustrated in FIG. 14.

[Flow of Orthogonal Transform Processing]

Next, an example of a flow of orthogonal transform processing to beexecuted in step S108 of FIG. 14 will be described with reference to aflowchart of FIG. 16.

When the orthogonal transform processing is started, the orthogonaltransform unit 104 determines in step S151 whether the optimal modeselected by the skip determination unit 132 is the orthogonal transformskip (TransformSkip mode). When it is determined to be the orthogonaltransform skip (TransformSkip mode), the processing proceeds to stepS152.

In step S152, the orthogonal transform unit 104 skips the orthogonaltransform processing and outputs the pre-orthogonal transformdifferential value of the current block. When the processing in stepS152 is ended, the processing returns to the process illustrated in FIG.14.

Further, in step S151 of FIG. 16, when it is determined not to be theorthogonal transform skip (TransformSkip mode), the processing proceedsto step S153.

In step S153, the orthogonal transform unit 104 performs the orthogonaltransform on the pre-orthogonal transform differential value of thecurrent block. In step S154, the orthogonal transform unit 104 outputsthe obtained orthogonal transform coefficient. When the processing instep S154 is ended, the processing returns to the process illustrated inFIG. 14.

[Flow of Quantization Processing]

Next, an example of a flow of the quantization processing to be executedin step S110 of FIG. 14 will be described with reference to a flowchartof FIG. 17.

When the quantization processing is started, the weighting coefficientgeneration unit 142 determines, in step S161, whether the optimal modeselected by the skip determination unit 132 is the orthogonal transformskip (TransformSkip mode). When it is determined to be the orthogonaltransform skip (TransformSkip mode), the processing proceeds to stepS162.

In step S162, the weighting coefficient generation unit 142 generates aweighting coefficient. When the processing in step S162 is ended, theprocessing proceeds to step S164.

Further, when it is determined not to be the orthogonal transform skip(TransformSkip mode) in step S161, the processing proceeds to step S163.

In step S163, the weighting coefficient generation unit 142 acquires aquantization matrix. When the processing in step S163 is ended, theprocessing proceeds to step S164.

In step S164, the quantization processing unit 143 performs thequantization of the orthogonal transform coefficient of the currentblock or the pre-orthogonal transform coefficient differential valueusing the weighting coefficient generated in step S162 and thequantization matrix acquired in step S163. In step S165, thequantization processing unit 143 supplies and transmits the quantizationmatrix and the applied weighting coefficient to the lossless encodingunit 106. When the processing in step S165 is ended, the quantizationprocessing is completed, and the processing returns to the processillustrated in FIG. 14.

[Flow of Deblocking Filter Processing]

Next, an example of a flow of the deblocking filter processing to beexecuted in step S114 of FIG. 14 will be described with reference to aflowchart of FIG. 18.

When the deblocking filter processing is started, the strengthadjustment unit 152 acquires mode information, motion vector, referenceframe information or the like in step S171.

In step S172, the strength adjustment unit 152 detects block boundariesof the TU, PU or the like. In step S173, the strength adjustment unit152 determines a Bs value based on such information. In step S174, thestrength adjustment unit 152 calculates a quantization parameter(boundary QP) in the block boundary by defining quantization parametersof both blocks as QP_P and QP_Q, as in Formula (3) below.

QP=(QP _(—) P+QP _(—) Q+1)>>1  (3)

In step S175, the strength adjustment unit 152 determines a β offsetvalue and a tc offset value using the boundary QP calculated asdescribed above. In step S176, the strength adjustment unit 152determines filters (strong, weak, and off) by processing the calculatedoffset values.

In step S177, the boundary determination unit 151 acquires a controlsignal of the current block from the skip determination unit 132 andacquires skip identification information (TransformSkipFlag) of theperipheral block from the lossless encoding unit 106.

In step S178, the boundary determination unit 151 determines whether thecurrent block boundary is the boundary between the orthogonal transformskip block and the non-orthogonal transform skip block.

When it is determined that the current block boundary is the boundarybetween the orthogonal transform skip block and the non-orthogonaltransform skip block, the processing proceeds to step S179. In stepS179, the strength adjustment unit 152 adjusts the strength of thedeblocking filter. When the processing in step S179 is ended, theprocessing proceeds to step S180.

Further, when it is determined in step S178 that the current blockboundary is not the boundary between the orthogonal transform skip blockand the non-orthogonal transform skip block, the processing proceeds tostep S180.

In step S180, the filtering unit 153 performs the deblocking filterprocessing. When the processing in step S180 is ended, the deblockingfilter processing is completed, and the processing returns to theprocess illustrated in FIG. 14.

By executing each processing operation as described above, the imageencoding device 100 can suppress the reduction of the encodingefficiency and suppress the deterioration of the image quality due tothe encoding/decoding.

2. Second Embodiment

[Image Decoding Device]

Next, decoding of the coded data (a coded stream) which is encoded asdescribed above will be described. FIG. 19 is a block diagramillustrating an example of a main configuration of an image decodingdevice corresponding to the image encoding device 100 in FIG. 1.

An image decoding device 200 illustrated in FIG. 19 decodes the codeddata generated by the image encoding device 100, using a decoding methodcorresponding to the coding system thereof.

As illustrated in FIG. 19, the image decoding device 200 includes anaccumulation buffer 201, a lossless decoding unit 202, an inversequantization unit 203, an inverse orthogonal transform unit 204, acomputation unit 205, a deblocking filter 206, a screen rearrangementbuffer 207, and a D/A converter 208. In addition, the image decodingdevice 200 includes a frame memory 209, a selection unit 210, an intraprediction unit 211, a motion prediction/compensation unit 212, and aselection unit 213.

Furthermore, the image decoding device 200 includes an inverseorthogonal transform skip unit 221.

The accumulation buffer 201 is also a reception unit for receiving thecoded data transmitted thereto. The accumulation buffer 201 receives andaccumulates the coded data transmitted therein, and supplies the codeddata to the lossless decoding unit 202 at a predetermining timing.Pieces of information necessary for decoding, such as the predictionmode information, are added to the coded data. The lossless decodingunit 202 decodes the information, which is supplied from theaccumulation buffer 201 and encoded by the lossless encoding unit 106 inFIG. 1, using a method corresponding to the coding system of thelossless encoding unit 106. The lossless decoding unit 202 supplies thequantized coefficient data of a difference image obtained by decoding tothe inverse quantization unit 203.

In addition, the lossless decoding unit 202 determines whether the intraprediction mode is selected or the inter prediction mode is selected, asthe optimal prediction mode, and supplies information relating to theoptimal prediction mode to one of the intra prediction unit 211 and themotion prediction/compensation unit 212, which is a mode determined tobe selected. In other words, for example, in the case where the interprediction mode is selected as the optimal prediction mode in the imageencoding device 100, the information relating to the optimal predictionmode is supplied to the intra prediction unit 211. In addition, forexample, when the inter prediction mode is selected as an optimalprediction mode in the image encoding device 100, the informationregarding the optimal prediction mode is supplied to the motionprediction/compensation unit 212.

Further, the lossless decoding unit 202 supplies information such as,for example, a quantization matrix or a quantization parameter, which isrequired for inverse quantization, to the inverse quantization unit 203.Further, the lossless decoding unit 202 supplies information such as,for example, skip enable information (transform_skip_enabled_flag) orskip identification information (TransformSkipFlag), which is requiredfor an inverse orthogonal transform, to the inverse orthogonal transformskip unit 221.

The inverse quantization unit 203 performs inverse quantization on thequantized coefficient data obtained by decoding of the lossless decodingunit 202 based on the control of the inverse orthogonal transform skipunit 221, using a method corresponding to the quantization method of thequantization unit 105 in FIG. 1. Further, the inverse quantization unit203 is a processing unit similar to the inverse quantization unit 108 ofthe image encoding device 100 in FIG. 1. That is, the description of theinverse quantization unit 203 can be also applied to that of the inversequantization unit 108. However, it is necessary to read input/outputdestination of data by appropriately varying it depending on devices.

The inverse quantization unit 203 supplies the obtained coefficient datato the inverse orthogonal transform unit 204.

Based on the control of the inverse orthogonal transform skip unit 221,the inverse orthogonal transform unit 204 performs inverse orthogonaltransform of the coefficient data (orthogonal transform coefficient orpre-orthogonal transform differential value) to be supplied from theinverse quantization unit 203 using a method corresponding to theorthogonal transform method of the orthogonal transform unit 104 in FIG.1, as necessary. Further, the inverse orthogonal transform unit 204 is aprocessing unit similar to the inverse orthogonal transform unit 109 ofthe image encoding device 100 in FIG. 1. That is, the description of theinverse orthogonal transform unit 204 can be also applied to that of theinverse orthogonal transform unit 109. However, it is necessary to readinput/output destination of data by appropriately varying it dependingon devices.

The inverse orthogonal transform unit 204 obtains decoded residual datacorresponding to the residual data before the orthogonal transform bythe inverse orthogonal transform processing in the image encoding device100. The decoded residual data obtained by the inverse orthogonaltransform is supplied to the computation unit 205. Further, a predictedimage is supplied to the computation unit 205 through the selection unit213 from the intra prediction unit 211 or the motionprediction/compensation unit 212.

The computation unit 205 adds the decoded residual data and thepredicted image and obtains decoded image data corresponding to imagedata before the predicted image is subtracted by the computation unit103 of the image encoding device 100. The computation unit 205 suppliesthe decoded image data to the deblocking filter 206.

The deblocking filter 206 appropriately performs deblocking filterprocessing on the supplied decoded image and supplies it to the screenrearrangement buffer 207. By performing the deblocking filter processingon the decoded image, the deblocking filter 206 removes the blockdistortion of the decoded image. Further, the deblocking filter 206 is aprocessing unit similar to the deblocking filter 111 of the imageencoding device 100 in FIG. 1.

The deblocking filter 206 supplies a filter processing result (a decodedimage after filter processing) to the screen rearrangement buffer 207and the frame memory 209. In addition, the decoded image output from thecomputation unit 205 may be supplied to the screen rearrangement buffer207 or the frame memory 209 without passing through the deblockingfilter 206. In other words, the filter processing performed by thedeblocking filter 206 may be omitted.

The screen rearrangement buffer 207 rearranges images. In other words,the order of the frames rearranged for the encoding order by the screenrearrangement buffer 102 in FIG. 1 is rearranged in the original displayorder. The D/A converter 208 D/A-converts the image supplied from thescreen rearrangement buffer 207 and outputs the image to a display notillustrated in the drawing to display the image thereon.

The frame memory 209 stores therein the supplied decoded image andsupplies the stored decoded image, as a reference image, to theselection unit 210, at a predetermined timing or on the basis of arequest from the outside, such as the intra prediction unit 211 or themotion prediction/compensation unit 212.

The selection unit 210 selects the supply destination of the referenceimage supplied from the frame memory 209. In the case of decoding anintra encoded image, the selection unit 210 supplies the reference imagesupplied from the frame memory 209 to the intra prediction unit 211. Inaddition, in the case of decoding an inter encoded image, the selectionunit 210 supplies the reference image supplied from the frame memory 209to the motion prediction/compensation unit 212.

To the intra prediction unit 211 is supplied information or the likeindicating the intra prediction mode, which is obtained by decodingheader information, appropriately from the lossless decoding unit 202.The intra prediction unit 211 performs intra prediction using thereference image acquired from the frame memory 209, in the intraprediction mode used in the intra prediction unit 114 in FIG. 1, andgenerates a predicted image. The intra prediction unit 211 supplies thegenerated predicted image to the selection unit 213.

The motion prediction/compensation unit 212 acquires information (theoptimal prediction mode information, the reference image information,and so forth), which is obtained by decoding the header information,from the lossless decoding unit 202.

The motion prediction/compensation unit 212 performs inter predictionusing the reference image acquired from the frame memory 209, in theinter prediction mode indicated by the optimal prediction modeinformation acquired from the lossless decoding unit 202, and generatesa predicted image.

The selection unit 213 supplies the predicted image from the intraprediction unit 211 or the predicted image from the motionprediction/compensation unit 212 to the computation unit 205. Inaddition, in the computation unit 205, the predicted image generatedusing the motion vector and the decoded residual data (difference imageinformation) from the inverse orthogonal transform unit 204 are added,and an original image is decoded. In other words, the motionprediction/compensation unit 212, the lossless decoding unit 202, theinverse quantization unit 203, the inverse orthogonal transform unit204, and the computation unit 205 are also a decoding unit for decodingthe coded data using the motion vector and generating the originalimage.

The inverse orthogonal transform skip unit 221 acquires the informationsupplied from the coding side through the lossless decoding unit 202 andcontrols execution of the inverse orthogonal transform processing in theinverse orthogonal transform unit 204 based on the information. Inaddition, the inverse orthogonal transform skip unit 221 controls theinverse quantization processing by the inverse quantization unit 203 andthe deblocking filter processing by the deblocking filter 206.

Thus, the image decoding device 200 can appropriately decode the codeddata. Accordingly, the image decoding device 200 can realize thesuppression of the reduction in the encoding efficiency and can realizethe suppression of the deterioration of the image quality dude to theencoding/decoding.

[Example of Configuration of Inverse Orthogonal Transform Skip Unit orthe Like]

FIG. 20 is a block diagram illustrating an example of a mainconfiguration of the inverse orthogonal transform skip unit 221 or thelike.

As illustrated in FIG. 20, the inverse orthogonal transform skip unit221 is configured to include a TransfomSkipFlag buffer 231 and a controlsignal generation unit 232.

The TransfomSkipFlag buffer 231 acquires and holds the skip enableinformation (transform_skip_enabled_flag) or the skip identificationinformation (TransfomSkipFlag) extracted from the coded data (bitstream) in the lossless decoding unit 202. The TransfomSkipFlag buffer231 supplies the held the skip enable information(transform_skip_enabled_flag) or the skip identification information(TransfomSkipFlag) to the control signal generation unit 232 atpredetermined timing or based on a demand.

The control signal generation unit 232 generates a control signaldepending on the skip enable information (transform_skip_enabled_flag)or the skip identification information (TransfomSkipFlag) supplied fromthe TransfomSkipFlag buffer 231 and supplies the control signal to theinverse quantization unit 203, the inverse orthogonal transform unit204, and the deblocking filter 206.

For example, when the orthogonal transform skip is disabled by the skipenable information (transform_skip_enabled_flag), the control signalgeneration unit 232 supplies a control signal as follows. That is, thecontrol signal generation unit 232 supplies a control signal forinstructing the inverse quantization unit 203 to perform the inversequantization using the quantization matrix. In addition, the controlsignal generation unit 232 supplies a control signal for instructing theinverse orthogonal transform unit 204 to perform the inverse orthogonaltransform. Further, the control signal generation unit 232 supplies acontrol signal for notifying the deblocking filter 206 that the currentblock is not the orthogonal transform skip block.

In addition, for example, when the orthogonal transform skip is enabledby the skip enable information (transform_skip_enabled_flag) and it isidentified by the skip identification information (TransfomSkipFlag)that the orthogonal transform skip is not applied at the time ofencoding of the current block, the control signal generation unit 232supplies the control signal in following manners. That is, the controlsignal generation unit 232 supplies the control signal for instructingthe inverse quantization unit 203 to perform the inverse quantizationusing the quantization matrix. In addition, the control signalgeneration unit 232 supplies the control signal instructing the inverseorthogonal transform unit 204 to perform the inverse orthogonaltransform. Further, the control signal generation unit 232 supplies thecontrol signal for notifying the deblocking filter 206 that the currentblock is not the orthogonal transform skip block. That is, the controlsignal generation unit 232 may supply the skip identificationinformation (TransfomSkipFlag) as the control signal to the deblockingfilter 206.

In addition, for example, when the orthogonal transform skip is enabledby the skip enable information (transform_skip_enabled_flag) and it isidentified by the skip identification information (TransfomSkipFlag)that the orthogonal transform skip is applied at the time of encoding ofthe current block, the control signal generation unit 232 supplies thecontrol signal in the following manners. That is, the control signalgeneration unit 232 supplies a control signal for instructing theinverse quantization unit 203 to perform the inverse quantization usingthe weighting coefficient. In addition, the control signal generationunit 232 supplies a control signal instructing for the inverseorthogonal transform unit 204 not to perform the inverse orthogonaltransform. Further, the control signal generation unit 232 supplies acontrol signal for notifying the deblocking filter 206 that the currentblock is the orthogonal transform skip block. That is, the controlsignal generation unit 232 may supply the skip identificationinformation (TransfomSkipFlag) as the control signal to the deblockingfilter 206.

As illustrated in FIG. 20, the inverse quantization unit 203 isconfigured to include a quantization matrix buffer 241, a weightingcoefficient generation unit 242, a quantization parameter buffer 243,and an inverse quantization unit 244.

The quantization matrix buffer 241 acquires and holds the quantizationmatrix, which is extracted from the SPS or the like of the coded data,by the lossless decoding unit 202. The quantization matrix istransmitted from the coding side and is used at the time of encoding.The quantization matrix buffer 241 supplies the held quantization matrixto the weighting coefficient generation unit 242 at predetermined timingor on demand. Further, when the weighting coefficient applied at thetime of encoding is transmitted from the coding side, the quantizationmatrix buffer 241 acquires the weighting coefficient and supplies it tothe weighting coefficient generation unit 242 as in the quantizationmatrix.

The weighting coefficient generation unit 242 acquires the controlsignal supplied from the control signal generation unit 232. Theweighting coefficient generation unit 242 grasps whether the orthogonaltransform skip is applied to the current block at the time of encoding,based on the control of the control signal and supplies the quantizationmatrix or the weighting coefficient to the inverse quantization unit 244based on the grasped information.

For example, when the orthogonal transform skip is not applied to thecurrent block at the time of encoding, the weighting coefficientgeneration unit 242 supplies the quantization matrix, which is suppliedfrom the quantization matrix buffer 241, of a mode designated by thecontrol signal to the inverse quantization unit 244.

In addition, for example, when the orthogonal transform skip is appliedto the current block at the time of encoding, the weighting coefficientgeneration unit 242 generates a weighting coefficient and supplies thegenerated weighting coefficient to the inverse quantization unit 244.

Further, a method of generating the weighting coefficient is arbitraryas long as the method is the same as a method in the coding side. Thatis, for example, in the image encoding device 100, when the weightingcoefficient generation unit 142 extracts the DC component of thequantization matrix supplied from the quantization matrix setting unit141 and sets the extracted DC component as a weighting coefficient, theweighting coefficient generation unit 242, similarly, also extracts theDC component of the quantization matrix supplied from the quantizationmatrix buffer 241 and also sets the extracted DC component as aweighting coefficient.

Further, in the image encoding device 100, when the weightingcoefficient generation unit 142 sets a weighting coefficient separatedfrom the quantization matrix supplied from the quantization matrixsetting unit 141, the weighting coefficient generation unit 242 alsosets a weighting coefficient separated from the quantization matrixsupplied from the quantization matrix buffer 241 in the same way. Atthis time, when the weighting coefficient applied at the time ofencoding is supplied from the coding side, the weighting coefficient isapplied.

Further, in the image encoding device 100, when the weightingcoefficient generation unit 142 calculates the weighting coefficientfrom the DC component of the quantization matrix of the peripheralblock, the weighting coefficient generation unit 242 also calculates theweighting coefficient from the DC component of the quantization matrixof the peripheral block in the same way.

The quantization parameter buffer 243 acquires and holds thequantization parameter extracted from the SPS or the like of the codeddata by the lossless decoding unit 202. The quantization parameter issupplied from the coding side and is used at the time of encoding. Thequantization parameter buffer 243 supplies the held quantizationparameter to the inverse quantization unit 244 at predetermined timingor on demand.

The inverse quantization unit 244 acquires the quantized coefficientextracted from the coded data by the lossless decoding unit 202. Theinverse quantization unit 244 also acquires the quantization parameterfrom the quantization parameter buffer 243 and acquires the quantizationmatrix or the weighting coefficient from the weighting coefficientgeneration unit 242. The inverse quantization unit 244 inverselyquantizes the quantized coefficient using them. This method of inversequantization corresponds to the method of quantization by thequantization processing unit 143 of the image encoding device 100.

That is, for example, when the orthogonal transform skip is not appliedto the current block at the time of encoding, the inverse quantizationunit inversely quantizes the quantized coefficient using thequantization matrix and the quantization parameter and supplies theobtained orthogonal transform coefficient to the inverse orthogonaltransform unit 204.

In addition, for example, when the orthogonal transform skip is appliedto the current block at the time of encoding, the inverse quantizationunit inversely quantizes the quantized coefficient using the weightingcoefficient and the quantization parameter and supplies the obtainedpre-orthogonal transform differential value to the inverse orthogonaltransform unit 204.

Thus, the inverse quantization unit 203 can appropriately perform theinverse quantization using a method corresponding to the quantization atthe time of encoding. That is, the inverse quantization unit 203 canappropriately quantize the quantized coefficient by the quantizationunit 105 of the image encoding device 100. Accordingly, the inversequantization unit 203 can appropriately perform the inverse quantizationso as to suppress the deterioration of the image quality. Therefore, theimage decoding device 200 can realize the suppression of thedeterioration of the image quality due to the encoding/decoding. Inother words, the image decoding device 200 can improve the encodingefficiency.

The inverse orthogonal transform unit 204 appropriately performs theinverse orthogonal transform on the inversely quantized coefficientsupplied from the inverse quantization unit 244 based on the controlsignal supplied from the control signal generation unit 232.

For example, when the current block is the block to which the orthogonaltransform skip is not applied at the time of encoding, the inverseorthogonal transform unit 204 grasps based on the control signal thatthe inversely quantized coefficient supplied from the inversequantization unit 244 is the orthogonal transform coefficient. That is,the inverse orthogonal transform unit 204 performs the inverseorthogonal transform on the orthogonal transform coefficient in a methodthat corresponds to the orthogonal transform of the orthogonal transformunit 104 in the image encoding device 100. Thus, the inversely quantizedcoefficient serving as a value of the frequency domain is converted intothe pre-orthogonal transform differential value (decoded residual data)serving as a value of the spatial domain. The inverse orthogonaltransform unit 204 supplies the decoded residual data to the computationunit 205.

In addition, for example, when the current block is the block to whichthe orthogonal transform skip is applied at the time of encoding, theinverse orthogonal transform unit 204 grasps based on the control signalthat the inversely quantized coefficient supplied from the inversequantization unit 244 is the pre-orthogonal transform differentialvalue. The inverse orthogonal transform unit 204 supplies thepre-orthogonal transform differential value serving as the value of thespatial domain to the computation unit 205, as the decoded residualdata.

Thus, the inverse orthogonal transform unit 204 can appropriatelyperform the inverse orthogonal transform in the method that correspondsto the orthogonal transform at the time of encoding. That is, forexample, the inverse orthogonal transform unit 204 can performappropriate processing on the coefficient generated by the orthogonaltransform unit 104 of the image encoding device 100. Accordingly, theinverse orthogonal transform unit 204 can appropriately perform theinverse orthogonal transform so as to suppress the deterioration of theimage quality. Therefore, the image decoding device 200 can realize thesuppression of the deterioration of the image quality due to theencoding/decoding. In other words, the image decoding device 200 canimprove the encoding efficiency.

As illustrated in FIG. 20, the deblocking filter 206 is configured toinclude a boundary determination unit 251, a strength adjustment unit252, and a filtering unit 253.

The boundary determination unit 251 is a processing unit similar to theboundary determination unit 151 of the image encoding device 100. Thecontrol signal (for example, skip identification information(TransformSkipFlag)) indicating whether the orthogonal transform skip isapplied to the current block at the time of encoding is supplied to theboundary determination unit 251. The boundary determination unit 251holds such information, determines whether the current block boundary isthe boundary between the orthogonal transform skip block and thenon-orthogonal transform skip block, and supplies the control signalindicating the determined result to the strength adjustment unit 252.

The strength adjustment unit 252 is a processing unit similar to thestrength adjustment unit 152 of the image encoding device 100. Thestrength adjustment unit 252 generates various parameters such as a Bsvalue, α, β, and tc and determines the strength of the deblocking filterbased on such values and the control signal supplied from the boundarydetermination unit 251. That is, the strength adjustment unit 252determines the strength of the deblocking filter based on variousparameters such as the generated Bs value, α, β, and tc when the currentblock boundary is not the boundary between the orthogonal transform skipblock and the non-orthogonal transform skip block. In addition, thestrength adjustment unit 252 additionally strengthens the filterstrength based on the control signal, for example, in any manner similarto the above manner when the current block boundary is the boundarybetween the orthogonal transform skip block and the non-orthogonaltransform skip block. The same method as in the strength adjustment unit152 is used for the determination and adjustment of the filter strength.That is, the filter strength applied at the time of encoding isreproduced.

The strength adjustment unit 252 notifies the filtering unit 253 of thefilter strength which is set in this manner.

The filtering unit 253 is a processing unit similar to the filteringunit 253 of the image encoding device 100. The filtering unit 253performs the deblocking filter processing on the decoded residual data(pre-deblocking filter pixel value) of the block boundary which issupplied from the computation unit 205, using the filter strengthsupplied from the strength adjustment unit 252. The filtering unit 253supplies a post-deblocking filter pixel value, which is obtained byperforming the deblocking filter processing, to the screen rearrangementbuffer 207 or the frame memory 209.

Thus, the deblocking filter 206 can perform the filter processing on theboundary between the orthogonal transform skip block and thenon-orthogonal transform skip block such that the stronger deblockingfilter is applied. Accordingly, the deterioration of the image qualityis further suppressed. That is, the image decoding device 200 canachieve the suppression of the deterioration of the image quality due tothe encoding/decoding. In other words, the image decoding device 200 canachieve the improvement of the encoding efficiency.

[Flow of Decoding Process]

Next, the flow in each processing operation to be executed by theabove-described image decoding device 200 will be described. First, anexample of the flow of a decoding process will be described withreference to a flowchart illustrated in FIG. 21.

When the decoding operation is started, the accumulation buffer 201accumulates the transmitted coded data in step S201. In step S202, thelossless decoding unit 202 decodes the bit stream (encoded differentialimage information) supplied from the accumulation buffer 201. That is,I-pictures, P-pictures, and B-pictures which are encoded by the losslessencoding unit 106 illustrated in FIG. 1 are decoded.

At this time, various types of information such as header informationother than the differential image information which are included in thebit stream are also decoded. In step S203, the TransformSkipFlag buffer231 of the inverse orthogonal transform skip unit 221 acquires the skipidentification information (TransformSkipFlag) extracted in the losslessdecoding unit 202. The control signal generation unit 232 of the inverseorthogonal transform skip unit 221 generates a control signal based onthe skip identification information (TransformSkipFlag) and supplies thecontrol signal to the weighting coefficient generation unit 242, theinverse orthogonal transform unit 204, and the boundary determinationunit 251.

In step S204, the inverse quantization unit 203 inversely quantizes aquantized coefficient obtained by the processing operation of step S202.In step S205, the inverse orthogonal transform unit 204 performs aninverse orthogonal transform on the inversely-quantized coefficientobtained in step S204 as necessary.

In step S206, the intra prediction unit 211 or the motionprediction/compensation unit 212 performs a prediction processingoperation and generates a predicted image. That is, the predictionprocessing operation is performed in the prediction mode which isdetermined by lossless decoding unit 202 and applied at the time ofencoding. More specifically, for example, when the intra prediction isapplied at the time of encoding, the intra prediction unit 211 generatesthe predicted image in the intra prediction mode which is regarded as anoptimal mode at the time of encoding. In addition, for example, when theinter prediction is applied at the time of encoding, the motionprediction/compensation unit 212 generates the predicted image in theinter prediction mode which is regarded as an optimal mode at the timeof encoding.

In step S207, the computation unit 205 adds the predicted imagegenerated in step S206 to the differential image information obtained bythe inverse orthogonal transform in step S205. In this manner, anoriginal image is decoded.

In step S208, the deblocking filter 206 appropriately performs thedeblocking filter processing operation on the decoded image obtained instep S205. Further, the deblocking filter processing operation isperformed in the same manner as the deblocking filter processingoperation at the time of encoding. That is, since the operation isperformed in the same manner as in the case where the operation isdescribed with reference to the flowchart illustrated in FIG. 18, thedetailed description of the deblocking filter processing is notpresented. In other words, the above-description with reference to theflowchart illustrated in FIG. 18 can be applied as the description ofthe deblocking filter processing.

In step S209, the screen rearrangement buffer 207 rearranges the imagesubjected to the filter processing in step S208. That is, the order offrames rearranged for encoding by the screen rearrangement buffer 102 ofthe image encoding device 100 is rearranged in the original displayingorder.

In step S210, the D/A converter 208 performs a D/A conversion on theimage in which the order of frames is rearranged in step S209. The imageis output to a display (not illustrated) and the image is displayed.

In step S211, the frame memory 209 stores the image subjected to thefilter processing in step S209.

When the processing operation in step S211 is ended, the decodingprocess is completed.

[Flow of Inverse Quantization Processing]

Next, an example of the flow of an inverse quantization processing to beexecuted in step S204 of FIG. 21 will be described with reference to aflowchart illustrated in FIG. 22.

When the inverse quantization processing is started, the weightingcoefficient generation unit 242 determines in step S231 whether thecurrent block is an orthogonal transform skip (TransformSkip) mode.

When it is determined that the current block is the orthogonal transformskip (TransformSkip) mode, the processing proceeds to step S232. In stepS232, the weighting coefficient generation unit 242 generates aweighting coefficient. When the processing in step S232 is ended, theprocessing proceeds to step S234.

Further, when it is determined in step S231 that the current block isnot the orthogonal transform skip (TransformSkip) mode, the processingproceeds to step S233. In step S233, the weighting coefficientgeneration unit 242 acquires a quantization matrix through theTransformSkipFlag buffer 231. When the processing in step S233 is ended,the processing proceeds to step S234.

In step S234, the inverse quantization unit 244 performs an inversequantization using the weighting coefficient generated in step S232 orthe quantization matrix generated in step S233.

When the processing in step S234 is ended, the inverse quantizationprocessing is completed, and the processing returns to the processingoperation illustrated in FIG. 21.

[Flow of Inverse Orthogonal Transform Processing]

Next, an example of the flow of an inverse orthogonal transformprocessing to be executed in step S205 of FIG. 21 will be described withreference to a flowchart illustrated in FIG. 23.

When the inverse orthogonal transform processing is started, the inverseorthogonal transform unit 204 determines in step S251 whether thecurrent block is an orthogonal transform orthogonal transform skip(TransformSkip) mode.

When it is determined that the current block is the orthogonal transformskip (TransformSkip) mode, the inverse orthogonal transform processingis ended, and the processing returns to the processing operationillustrated in FIG. 21.

Further, when it is determined in step S251 of FIG. 23 that the currentblock is not the orthogonal transform skip (TransformSkip) mode, theprocessing proceeds to step S252. In step S252, the inverse orthogonaltransform unit 204 performs the inverse orthogonal transform on theinversely-quantized coefficient.

When the processing in step S252 is ended, the inverse orthogonaltransform processing is completed, the processing returns to theprocessing operation illustrated in FIG. 21.

By executing each processing operation as described above, the imagedecoding device 200 can correctly decode the coded data, therebyachieving the suppression of the reduction of the encoding efficiencyand the suppression of the deterioration of the image quality due to theencoding/decoding.

Further, in the above, it is described that the skip enable information(transform_skip_enabled_flag) is transmitted to the SPS, but a method oftransmitting the skip enable information is not limited thereto.

For example, when a picture such as, for example, a natural image, inwhich the orthogonal transform skip (TransformSkip) is not valid and apicture such as an image including captions which contain a block towhich the orthogonal transform skip (TransformSkip) is applied arepresent in one sequence, if the orthogonal transform skip is enabled insequence unit, the skip identification information (TransformSkipFlag)has to be transmitted to all of the blocks of all the pictures in thesequence, and thus it is inefficient. If the orthogonal transform skipis disabled, there is no need to transmit the skip identificationinformation (TransformSkipFlag). For this reason, particularly, as theratio of the picture containing the block, to which the orthogonaltransform skip (TransformSkip) is applied, becomes smaller, there is aconcern to unnecessarily reduced encoding efficiency.

Thus, the orthogonal transform skip is not limited to be enabled insequence units but is preferably enabled in unit smaller than thesequence unit. For this reason, the skip enable information may betransmitted to any position of bit stream such as, for example, PPS orslice header other than the SPS. Naturally, the skip enable informationmay be transmitted separately from the bit stream.

Further, in the above, it is described that the skip enable information(transform_skip_enabled_flag) is set by the user or the like, but asetting method (control method of enabling/disabling the orthogonaltransform skip) of the skip enable information(transform_skip_enabled_flag) is arbitrary. For example, the skip enableinformation may be set according to the content of the image to beencoded.

For example, when the orthogonal transform skip is disabled in aninitial state and a genre of a program is detected in an electronicprogram guide (EPG) or the like, if the detected genre is an animation,it is preferable to set the skip enable information(transform_skip_enabled_flag) so as to enable the orthogonal transformskip. Thus, the control of the enabling/disabling of the orthogonaltransform skip may be performed based on information other than a movingimage.

Furthermore, for example, a detection of an CM (commercial broadcasting)is performed in a state (for example, in the case where the program isan animation) where the orthogonal transform skip is enabled, theorthogonal transform skip may be disabled during the CM broadcasting,and the orthogonal transform skip may be enabled during the programbroadcasting. Thus, the control of the enabling/disabling of theorthogonal transform skip may be performed based on analysis resultsobtained by analyzing the content of the moving image.

Naturally, the content (moving image) subjected to such controlprocessing is not limited to the broadcasting content. For example, itmay be a content which is recorded in a recording medium such as, forexample, a hard disk or a Blu-ray (registered trademark) disk and acontent which is downloaded (or streaming-reproduced) from the outsidethrough an electric communication line such as an Internet.

3. Third Embodiment

[Transmission Control of Skip Enable Information]

However, as described above, the orthogonal transform skip can beapplied to 4×4 luminance orthogonal transform block (TU of luminancecomponent) or 4×4 chrominance orthogonal transform block (TU ofchrominance component).

On the contrary, for example, a minimum size of the TU is designated bysyntax which is referred to as log 2_min_transform_block_size_minus2 inthe HEVC or the like. For example, in the sequence parameter set (SPS)illustrated in FIG. 4, the minimum size of the TU is designated by thelog 2_min_transform_block_size_minus2 indicated in the sixth row fromthe bottom.

When the minimum size designated by the log2_min_transform_block_size_minus2 is larger than 4×4, the 4×4 orthogonaltransform block (TU) is not present. That is, in this case, there is nopossibility that the orthogonal transform skip (TransformSkip) isapplied. Accordingly, there is no need to transmit the skip enableinformation (transform_skip_enabled_flag) indicating whether or not toenable/disable the orthogonal transform skip (TransformSkip). In otherwords, when the skip enable information is transmitted despite theminimum size of the TU is larger than 4×4, the amount of informationunnecessarily increases, and thus the encoding efficiency may beunnecessarily reduced.

Here, as described above, when the minimum size of the TU is larger than4×4, the transmission of the skip enable information may be omitted. Inother words, the skip enable information may be transmitted only in thecase where the minimum size of the TU is 4×4 (or less) (only in the casewhere the TU having the size of 4×4 is present).

[Transmission in Sequence Parameter Set]

A transmission method of the skip enable information(transform_skip_enabled_flag) is arbitrary.

For example, the skip enable information may be transmitted to thesequence parameter set (SPS). Some example of the syntax of the SPS insuch a case is illustrated in FIG. 24.

As illustrated in FIG. 24, a log 2_min_transform_block_size_minus2indicating the minimum size of the orthogonal transform block (TU) isset in the fifth row from the top in FIG. 24. The log2_min_transform_block_size_minus2 is a syntax indicating the minimumsize of the orthogonal transform block (TU) in the sequencecorresponding to the SPS.

On the contrary, as indicated in the fifth row from the bottom in FIG.24, it is confirmed whether the minimum size of the TU is 4×4 (if (log2_min_transform_block_size_minus2==0)), and the skip enable information(transform_skip_enabled_flag) is set only in the case where the minimumsize of the TU is 4×4, as indicated in the fourth row from the bottom inFIG. 24. That is, the skip enable information is transmitted only in thecase where the minimum size of the TU is 4×4; otherwise, it iscontrolled so as not to be transmitted. Further, in this case, the skipenable information (transform_skip_enabled_flag) is transmitted only inthe SPS. In addition, when skip enable information(transform_skip_enabled_flag) is set, the value is set based on anyinformation such as, for example, a user's instruction.

Furthermore, the transmission control of the skip enable information isperformed by the lossless encoding unit 106. Consequently, the imageencoding device 100 can transmit the skip enable information only whennecessary, thereby suppressing the reduction of the encoding efficiencyand suppressing the deterioration of the image quality due to theencoding/decoding.

[Transmission to Picture Parameter Set]

In addition, the skip enable information (transform_skip_enabled_flag)may be transmitted to, for example, the picture parameter set (PPS).Some example of the syntax of the PPS in such a case is illustrated inFIG. 25.

As illustrated in FIG. 25, a pps_log 2_min_transform_block_size_minus2indicating the minimum size of the orthogonal transform block (TU) isset in the third row from the top in FIG. 25. The pps_log2_min_transform_block_size_minus2 is a syntax indicating the minimumsize of the orthogonal transform block (TU) in the picture correspondingto the PPS. That is, even when the above-described log2_min_transform_block_size_minus2 is set in the SPS, the pps_log2_min_transform_block_size_minus2 can be set in the PPS. However, inthis case, the skip enable information (transform_skip_enabled_flag) istransmitted only in the PPS.

On the contrary, as indicated in the fourth row form the top in FIG. 25,it is confirmed whether the minimum size of the TU is 4×4 (if (pps_log2_min_transform_block_size_minus2==0)), and the skip enable information(transform_skip_enabled_flag) is set only in the case where the minimumsize of the TU is 4×4, as indicated in the fifth row from the top inFIG. 25. That is, even in this case, the skip enable information istransmitted only in the case where the minimum size of the TU is 4×4;otherwise, it is controlled so as not to be transmitted. When the skipenable information (transform_skip_enabled_flag) is set, the value isset based on any information such as, for example, a user's instruction.

Even in this case, the transmission control of the skip enableinformation is performed by the lossless encoding unit 106.Consequently, the image encoding device 100 can transmit the skip enableinformation only when necessary, thereby suppressing the reduction ofthe encoding efficiency and suppressing the deterioration of the imagequality due to the encoding/decoding.

Further, the position of the syntax of the pps_log2_min_transform_block_size_minus2 in the PPS is not limited to theexample in FIG. 25. The pps_log 2_min_transform_block_size_minus2 may beset at the position prior to that of the skip enable information(transform_skip_enabled_flag). Thus, it enables the SPS and PPS to beindependent in terms of parsing, and both of them can be independentlydecoded.

[Transmission to Slice Header]

Further, even though not illustrated, the skip enable information(transform_skip_enabled_flag) may be transmitted to, for example, aslice header.

In the slice header, the log 2_min_transform_block_size_minus2 is notset. In the slice, a picture to which the slice belongs is set. That is,the pps_log 2_min_transform_block_size_minus2 of the PPS is referenced.

In the slice header, the skip enable information is set as follows.

if(pps_log2_min_transform_block_size_minus2 == 0) {transcorm_skip_enabled_flag }

That is, in this case, skip enable information(transform_skip_enabled_flag) is set in the same manner as in the caseof the PPS. However, in this case, the skip enable information(transform_skip_enabled_flag) is transmitted only in the slice header.

Even in this case, the skip enable information is transmitted only inthe case where the minimum size of the TU is 4×4; otherwise, it iscontrolled so as not to be transmitted. In addition, when the skipenable information (transform_skip_enabled_flag) is set, the value isset based on any information such as, for example, a user's instruction.Further, the transmission control of the skip enable information isperformed by the lossless encoding unit 106.

Consequently, the image encoding device 100 can transmit the skip enableinformation only when necessary, thereby suppressing the reduction ofthe encoding efficiency and suppressing the deterioration of the imagequality due to the encoding/decoding.

As described above, the transmission control of the skip enableinformation can be performed in an arbitrary unit. Naturally, it may bea unit other than the example described above.

[Flow of Skip-Enable-Information Generation Processing]

Next, an example of a flow of a skip-enable-information generationprocessing will be described with reference to a flowchart in FIG. 26,which controls the transmission of the skip enable information asdescribed above.

This processing operation can be performed in any timing if it isperformed before the orthogonal transform processing, but for example,it may be performed in step S101 of the encoding process in FIG. 14.

When the skip-enable-information generation processing is started, thelossless encoding unit 106 sets the log2_min_transform_block_size_minus2 in step S301.

In step S302, the lossless encoding unit 106 determines whether theminimum size of the orthogonal transform block (TU) is 4×4 (or less).

If “0” is set to the value of the log 2_min_transform_block_size_minus2by the processing in step S301 and it is determined that the minimumsize of the orthogonal transform block (TU) is 4×4 (or less), theprocessing proceeds to step S303.

In step S303, the lossless encoding unit 106 sets the skip enableinformation (transform_skip_enabled_flag). When the processing in stepS303 is ended, the skip-enable-information generation processing iscompleted, and the processing operation returns to, for example, theencoding process in FIG. 14.

Further, if “1” or more is set to the value of the log2_min_transform_block_size_minus2 by the processing of S301 in step S302of FIG. 26 and it is determined that the minimum size of the orthogonaltransform block (TU) is larger than 4×4, the processing (setting of theskip enable information (transform_skip_enabled_flag)) in step S303 isomitted, the skip-enable-information generation processing is completed,and the processing operation returns to, for example, the encodingprocess in FIG. 14.

As described above, by the skip-enable-information generationprocessing, the image encoding device 100 can suppress the reduction ofthe encoding efficiency and suppress the deterioration of the imagequality due to the encoding/decoding.

Further, FIG. 26 illustrates the description of the flow of theskip-enable-information generation processing when the skip enableinformation is transmitted to the SPS, but may be applied even when theskip enable information is transmitted to the PPS or the slice header.In the case where the skip enable information is transmitted to the PPSor the slice header, since the flow of the processing operation isbasically similar to the flow of the processing operation which isdescribed with reference to FIG. 26 except that the syntax set in stepS301 is pps_log 2_min_transform_block_size_minus2 of PPS, thedescription thereof will be not presented.

[Reception of Skip Enable Information in Image Decoding Device]

When the transmission of the skip enable information is controlled asdescribed above in the image encoding device 100, there are a case wherethe skip enable information is transmitted and a case where the skipenable information is not transmitted. Therefore, in the similar manner,the image decoding device 200 may control whether or not to accept(whether or not to receive) the skip enable information from the settingof the minimum size of the orthogonal transform block (TU). Thus, theimage decoding device 200 can suppress the increase in unnecessarywaiting time, for example, time waiting for the skip enable informationwhich is not transmitted.

That is, as in the image encoding device 100, the image decoding device200 controls whether or not to receive the skip enable information basedon the values (depending on whether the minimum size of the TU is 4×4)with reference to the log 2_min_transform_block_size_minus2 transmittedto the SPS and the pps_log 2_min_transform_block_size_minus2 transmittedto the PPS. For example, such control is performed by the losslessdecoding unit 202 of the image decoding device 200.

[Flow of Skip-Enable-Information Reception Processing]

Next, an example of a flow of the skip-enable-information generationprocessing will be described with reference to a flowchart in FIG. 27,which controls the transmission of the skip enable information asdescribed above. This processing operation may be performed prior toacquiring the skip identification information (TransfomSkipFlag) (forexample, prior to step S203 in FIG. 21).

When the skip-enable-information reception processing is started, thelossless decoding unit 202 receives the log2_min_transform_block_size_minus2 in step S321. In step S322, thelossless decoding unit 202 determines whether the minimum size of the TUis 4×4 (or less), based on the received value.

If the value of the log 2_min_transform_block_size_minus2 is “0” and itis determined that the minimum size of the TU is 4×4 (or less), theprocessing proceeds to step S323. In step S323, the lossless decodingunit 202 performs the reception of the skip enable information(transform_skip_enabled_flag). When the processing in step S323 isended, the skip-enable-information reception processing is completed,and the processing operation returns to, for example, the decodingprocess in FIG. 21.

Further, if the value of the log 2_min_transform_block_size_minus2 is“1” or more in step S322 of FIG. 27 and it is determined that theminimum size of the TU is larger than 4×4, the skip-enable-informationreception processing is completed, and the processing operation returnsto, for example, the decoding process in FIG. 21.

As described above, by the skip-enable-information reception processing,the image decoding device 200 can suppress the reduction of the encodingefficiency and suppress the deterioration of the image quality due tothe encoding/decoding.

Further, FIG. 27 illustrates the description of the flow of theskip-enable-information generation processing when the skip enableinformation is transmitted to the SPS, and the description may beapplied even when the skip enable information is transmitted to the PPSor the slice header since the flow of the processing operation isbasically similar to the flow of the processing operation which isdescribed with reference to FIG. 27 except that the syntax received instep S321 is pps_log 2_min_transform_block_size_minus2 of PPS, thus thedescription thereof will be not presented.

The above description has been made based on the HEVC coding system, butthe scope of the present technology is not limited thereto and thepresent technology can be applied to all of the image informationencoding device and decoding device based on the coding system using theorthogonal transform skip (TransformSkip) as proposed in Non-PatentDocument 2.

4. Fourth Embodiment

[Application to Multi-Image Point Encoding/Multiple Viewpoint ImageDecoding]

The series of processing operations described above may be applied tomultiple viewpoint image encoding/multiple viewpoint image decoding.FIG. 28 illustrates an example of a multiple viewpoint image codingsystem.

As illustrated in FIG. 28, a multiple viewpoint image includes imagesfrom a plurality of viewpoints and an image from a predeterminedviewpoint out of the plural viewpoints is designated as a base viewimage. An image from each viewpoint other than the base view image istreated as a non-base view image.

In the case of performing such multiple viewpoint image encoding as inFIG. 28, a difference in quantization parameter may be taken inindividual views (the same view).

(1) base-view:

-   -   (1-1) dQP(base view)=Current_CU_QP(base view)−LCU_QP(base view)    -   (1-2) dQP(base view)=Current_CU_QP(base        view)−Previsous_CU_QP(base view)    -   (1-3) dQP(base view)=Current_CU_QP(base view)−Slice_QP(base        view)

(2) non-base-view:

-   -   (2-1) dQP(non-base view)=Current_CU_QP(non-base        view)−LCU_QP(non-base view)    -   (2-2) dQP(non-base view)=CurrentQP(non-base        view)−PrevisousQP(non-base view)    -   (2-3) dQP(non-base view)=Current_CU_QP(non-base        view)−Slice_QP(non-base view)

In the case of performing the multiple viewpoint image encoding, adifference in quantization parameter may be taken in individual views(different views).

(3) base-view/non-base view:

-   -   (3-1) dQP(inter-view)=Slice_QP(base view)−Slice_QP(non-base        view)    -   (3-2) dQP(inter-view)=LCU_QP(base view)−LCU_QP(non-base view)

(4) non-base view/non-base view:

-   -   (4-1) dQP(inter-view)=Slice_QP(non-base view        i)−Slice_QP(non-base view j)    -   (4-2) dQP(inter-view)=LCU_QP(non-base view i)−LCU_(—)QP(non-base        view j)

In this case, the items (1) to (4) described above may be used incombination. For example, in the non-base views, a technique (using 3-1and 2-3 in combination) for taking a difference in quantizationparameter between a base view and a non-base view on a slice level basisand a technique (using 3-2 and 2-1 in combination) for taking adifference in quantization parameter between a base view and a non-baseview on an LCU level basis may be considered. Accordingly, it ispossible to improve the encoding efficiency by repeatedly applying thedifference even in the case of performing the multiple viewpointencoding.

Similarly to the techniques described above, it is also possible to seta flag identifying whether a dQP whose value is not 0 is present withrespect to each dQP described above.

[Multiple Viewpoint Image Encoding Device]

FIG. 29 is a diagram illustrating a multiple viewpoint image encodingdevice performing the above-described multiple viewpoint image encoding.As illustrated in FIG. 29, a multiple viewpoint image encoding device600 includes an encoding unit 601, an encoding unit 602, and amultiplexer 603.

The encoding unit 601 encodes a base view image and generates a baseview image coded stream. The encoding unit 602 encodes a non-base viewimage and generates a non-base view image coded stream. The multiplexer603 multiplexes the base view image coded stream generated in theencoding unit 601 and the non-base view image coded stream generated inthe encoding unit 602 and generates a multiple viewpoint image codedstream.

The image encoding device 100 (FIG. 1) may be applied to the encodingunit 601 and the encoding unit 602 of the multiple viewpoint imageencoding device 600. In this case, the multiple viewpoint image encodingdevice 600 sets a difference value between a quantization parameter setby the encoding unit 601 and a quantization parameter set by theencoding unit 602 and transmits the difference value.

In addition, the orthogonal transform skip processing may beindependently performed on each view in each of the encoding unit 601and the encoding unit 602. In addition, the quantization processing, thedeblocking filter processing or the like may be also independentlyperformed on each view in each of the encoding unit 601 and the encodingunit 602. In this case, the information such as the quantization matrix,various flags, and the weighting coefficient is included in, forexample, the coded stream for each view, and thus the information issupplied to the multiplexer 603 from the encoding unit 601 and theencoding unit 602. The supplied information is multiplexed in themultiplexer 603 and is then transmitted to the decoding side in a stateof being included in the multiple viewpoint image coded stream.

Further, with respect to some or the entire orthogonal transform skipprocessing, the quantization processing, and the deblocking filterprocessing, the processing in one of the encoding unit 601 and theencoding unit 602 may be reflected in that in the other of them.Further, some or the entire information, such as the information on theskip of the orthogonal transform processing including the skip enableinformation or the skip identification information, the information onthe quantization, and the information on the deblocking filter may beshared in the encoding unit 601 and the encoding unit 602. For example,some or all of processed results (or obtained information or the like)obtained by performing the orthogonal transform skip processing, thequantization processing, and the deblocking filter processing on thebase view image in the encoding unit 601 may be supplied to the encodingunit 602 and be reflected in such processing operations for the non-baseview image performed in the encoding unit 602. Naturally, on thecontrary, processed results (or obtained information or the like)obtained by performing the orthogonal transform skip processing, thequantization processing, and the deblocking filter processing on thenon-base view image in the encoding unit 602 may be supplied to theencoding unit 601 and be reflected in such processing operations for thebase view image performed in the encoding unit 601.

[Multiple Viewpoint Image Decoding Device]

FIG. 30 is a diagram illustrating a multiple viewpoint image decodingdevice for performing the above-described multiple viewpoint imagedecoding. As illustrated in FIG. 30, a multiple viewpoint image decodingdevice 610 includes a demultiplexer 611, a decoding unit 612, and adecoding unit 613.

The demultiplexer 611 demultiplexes the multiple viewpoint image codedstream in which the base view image coded stream and the non-base viewimage coded stream are multiplexed, and extracts the base view imagecoded stream and the non-base view image coded stream. The decoding unit612 decodes the base view image coded stream extracted by thedemultiplexer 611 and obtains a base view image. The decoding unit 613decodes the non-base view image coded stream extracted by thedemultiplexer 611 and obtains a non-base view image.

The image decoding device 200 (FIG. 19) may be applied to the decodingunit 612 and the decoding unit 613 of the multiple viewpoint imagedecoding device 610. In this case, the decoding unit 612 and thedecoding unit 613 of the multiple viewpoint image decoding device 610set a quantization parameter using a difference value between aquantization parameter set by the encoding unit 601 of the multipleviewpoint image encoding device 600 and a quantization parameter set bythe encoding unit 602 and perform an inverse quantization.

In addition, the orthogonal transform skip processing may beindependently performed on each view in each of the decoding unit 612and the decoding unit 613. In addition, the inverse quantizationprocessing, the deblocking filter processing or the like may be alsoindependently performed in each of the decoding unit 612 and thedecoding unit 613. In this case, the information such as thequantization matrix, various flags, and the weighting coefficientincluded in the multiple viewpoint image coded stream and transmittedfrom the coding side is separated in the demultiplexer 611 for each viewand is then supplied to the decoding unit 612 and the decoding unit 613in a state of being included in the coded stream for each view.

Further, with respect to some or the entire inverse orthogonal transformskip processing, the inverse quantization processing, and the deblockingfilter processing, the processing, the decoding unit 612 and thedecoding unit 613 may be reflected one another. Further, some or theentire information, such as the information on the skip of the inverseorthogonal transform processing including the skip enable information orthe skip identification information, the information on the inversequantization, and the information on the inverse deblocking filter maybe shared in the decoding unit 612 and the decoding unit 613. Forexample, some or all of processed results (or obtained information orthe like) obtained by performing the inverse orthogonal transform skipprocessing, the inverse quantization processing, and the deblockingfilter processing on the base view image coded stream in the decodingunit 612 may be supplied to the decoding unit 613 and be reflected insuch processing operations for the non-base view image coded streamperformed in the decoding unit 613 (for example, omission of duplicatedprocessing). Naturally, on the contrary, processed results (or obtainedinformation) obtained by performing the inverse orthogonal transformskip processing, the inverse quantization processing, and the deblockingfilter processing on the non-base view image coded stream in thedecoding unit 613 may be supplied to the decoding unit 612 and bereflected in such processing operations for the base view image codedstream performed in the decoding unit 612 (for example, omission ofduplicated processing).

5. Fifth Embodiment

[Application to Hierarchical Image Point Encoding/Hierarchical ImageDecoding]

The series of processing operations described above may be applied tohierarchical image encoding/hierarchical image decoding. FIG. 31illustrates an example of a multiple viewpoint image coding system.

As illustrated in FIG. 31, a hierarchical image includes images in aplurality of layers (resolutions), and an image of a predetermined layerout of the plural resolutions is designated as a base layer image. Animage of each layer other than the base layer image is treated as anon-base layer image.

In the case of performing the hierarchical image encoding (spatialscalability) illustrated in FIG. 31, a difference in quantizationparameter may be taken in each layer (the same layer).

(1) base-layer:

-   -   (1-1) dQP(base layer)=Current_CU_QP(base layer)−LCU_QP(base        layer)    -   (1-2) dQP(base layer)=Current_CU_QP(base        layer)−Previsous_CU_QP(base layer) (1-3) dQP(base        layer)=Current_CU_QP(base layer)−Slice_QP(base layer)

(2) non-base-layer:

-   -   (2-1) dQP(non-base layer)=Current_CU_QP(non-base        layer)−LCU_QP(non-base layer)    -   (2-2) dQP(non-base layer)=CurrentQP(non-base        layer)−PrevisousQP(non-base layer)    -   (2-3) dQP(non-base layer)=Current_CU_QP(non-base        layer)−Slice_QP(non-base layer)

In the case of the hierarchical encoding, a difference in quantizationparameter may be taken in each layer (different layers).

(3) base-layer/non-base layer:

-   -   (3-1) dQP(inter-layer)=Slice_QP(base layer)−Slice_QP(non-base        layer)    -   (3-2) dQP(inter-layer)=LCU_QP(base layer)−LCU_QP(non-base layer)

(4) non-base layer/non-base layer:

-   -   (4-1) dQP(inter-layer)=Slice_QP(non-base layer        i)−Slice_QP(non-base layer j)    -   (4-2) dQP(inter-layer)=LCU_QP(non-base layer i)−LCU_QP(non-base        layer j)

In this case, the items (1) to (4) described above may be used incombination. For example, in the non-base layers, a technique (using 3-1and 2-3 in combination) for taking a difference in quantizationparameter between a base layer and a non-base layer on a slice levelbasis and a technique (using 3-2 and 2-1 in combination) for taking adifference in quantization parameter between a base layer and a non-baselayer on an LCU level basis may be considered. Accordingly, it ispossible to improve the encoding efficiency by repeatedly applying thedifference even in the case of performing the hierarchical encoding.

Similarly to the techniques described above, it is also possible to seta flag identifying whether a dQP whose value is not 0 is present withrespect to each dQP described above.

[Hierarchical Image Encoding Device]

FIG. 32 is a diagram illustrating a hierarchical image encoding devicefor performing the above-described hierarchical image encoding. Asillustrated in FIG. 32, a hierarchical image encoding device 620includes an encoding unit 621, an encoding unit 622, and a multiplexer623.

The encoding unit 621 encodes a base layer image and generates a baselayer image coded stream. The encoding unit 622 encodes a non-base layerimage and generates a non-base layer image coded stream. The multiplexer623 multiplexes the base layer image coded stream generated in theencoding unit 621 and the non-base layer image coded stream generated inthe encoding unit 622 and generates a hierarchical image coded stream.

The image encoding device 100 (FIG. 1) may be applied to the encodingunit 621 and the encoding unit 622 of the hierarchical image encodingdevice 620. In this case, the hierarchical image encoding device 620sets a difference value between a quantization parameter set by theencoding unit 621 and a quantization parameter set by the encoding unit622 and transmits the difference value.

In addition, the orthogonal transform skip processing may beindependently performed on each layer in each of the encoding unit 621and the encoding unit 622. In addition, the quantization processing, thedeblocking filter processing or the like may be also independentlyperformed on each layer in each of the encoding unit 621 and theencoding unit 622. In this case, the information such as thequantization matrix, various flags, and the weighting coefficient isincluded in, for example, the coded stream for each layer, and thus theinformation is supplied to the multiplexer 623 from the encoding unit621 and the encoding unit 622. The supplied information is multiplexedin the multiplexer 623 and is then transmitted to the decoding side in astate of being included in the hierarchical image coded stream.

Further, with respect to some or the entire orthogonal transform skipprocessing, the quantization processing, and the deblocking filterprocessing, the processing of the encoding unit 621 and the encodingunit 622 may be reflected one another. Further, some or the entireinformation, such as the information on the skip of the orthogonaltransform processing including the skip enable information or the skipidentification information, the information on the quantization, and theinformation on the deblocking filter may be shared in the encoding unit621 and the encoding unit 622. For example, some or all of processedresults (or obtained information) obtained by performing the orthogonaltransform skip processing, the quantization processing, and thedeblocking filter processing on the base layer image in the encodingunit 621 may be supplied to the encoding unit 622 and may be reflectedon such processing operations for the non-base layer image performed inthe encoding unit 622 (for example, omission of duplicated processing).Naturally, on the contrary, processed results (or obtained information)obtained by performing the orthogonal transform skip processing, thequantization processing, and the deblocking filter processing on thenon-base layer image in the encoding unit 622 may be supplied to theencoding unit 621 and may be reflected on such processing operations forthe base layer image performed in the encoding unit 621 (for example,omission of duplicated processing).

[Hierarchical Image Decoding Device]

FIG. 33 is a diagram illustrating a hierarchical image decoding devicefor performing the above-described hierarchical image decoding. Asillustrated in FIG. 33, a hierarchical image decoding device 630includes a demultiplexer 631, a decoding unit 632, and a decoding unit633.

The demultiplexer 631 demultiplexes a hierarchical image coded stream towhich the base layer image coded stream and the non-base layer imagecoded stream are multiplexed and extracts the base layer image codedstream and the non-base layer image coded stream. The decoding unit 632decodes the base layer image coded stream extracted by the demultiplexer631 and obtains a base layer image. The decoding unit 633 decodes thenon-base layer image coded stream extracted by the demultiplexer 631 andobtains a non-base layer image.

The image decoding device 200 (FIG. 19) may be applied to the decodingunit 632 and the decoding unit 633 of the hierarchical image decodingdevice 630. In this case, the decoding unit 632 and the decoding unit633 of the hierarchical image decoding device 630 set a quantizationparameter using a difference value between a quantization parameter setby the encoding unit 621 of the hierarchical image encoding device 620and a quantization parameter set by the encoding unit 622 and perform aninverse quantization.

In addition, the orthogonal transform skip processing may beindependently performed on each view in each of the decoding unit 632and the decoding unit 633. In addition, the inverse quantizationprocessing, the deblocking filter processing or the like may be alsoindependently performed in the decoding unit 632 and the decoding unit633. In this case, the information such as the quantization matrix,various flags, and the weighting coefficient included in thehierarchical image coded stream and transmitted from the coding side isseparated in the demultiplexer 631 for each layer and is then suppliedto the decoding unit 632 and the decoding unit 633 in a state of beingincluded in the coded stream for each layer.

Further, with respect to some or the entire inverse orthogonal transformskip processing, the inverse quantization processing, and the deblockingfilter processing, the processing, the decoding unit 632 and thedecoding unit 633 may be reflected one another. Further, some or theentire information, such as the information on the skip of the inverseorthogonal transform processing including the skip enable information orthe skip identification information, the information on the inversequantization, and the information on the inverse deblocking filter maybe shared in the decoding unit 632 and the decoding unit 633. Forexample, some or all of processed results (or obtained information orthe like) obtained by performing the inverse orthogonal transform skipprocessing, the inverse quantization processing, and the deblockingfilter processing on the base layer image coded stream in the decodingunit 632 may be supplied to the decoding unit 633 and may be reflectedin such processing operations for the non-base layer image coded streamperformed in the decoding unit 633 (for example, omission of duplicatedprocessing). Naturally, on the contrary, processed results (or obtainedinformation) obtained by performing the inverse orthogonal transformskip processing, the inverse quantization processing, and the deblockingfilter processing on the non-base layer image coded stream in thedecoding unit 633 may be supplied to the decoding unit 632 and may bereflected in such processing operations for the base view image codedstream performed in the decoding unit 632 (for example, omission ofduplicated processing).

In addition, the present technology can be applied to image encodingdevices and image decoding devices that are used for receiving imageinformation (bit streams) compressed through orthogonal transforms suchas discrete cosine transforms and motion compensation as in MPEG, H.26xor the like, for example, through a network media such as satellitebroadcasting, cable TV, the Internet, or a mobile phone. Further, thepresent technology can also be applied to image encoding devices andimage decoding devices that are used when the compressed imageinformation is processed on a storage medium such as an optical ormagnetic disk and a flash memory. Further, the present technology canalso be applied to a quantization device or an inverse quantizationdevice included in the image encoding device, the image decoding deviceand the like.

6. Sixth Embodiment

[Computer]

The above-described series of processing operations may be executed byhardware or executed by software. In a case where the series ofprocessing operations are executed by the software, programsconstituting the software are installed into a computer. Here, examplesof the computer include a computer incorporated into dedicated hardware,a general-purpose personal computer capable of executing variousfunctions by installing various kinds of programs, and so forth.

FIG. 34 is a block diagram illustrating an example of a configuration ofthe hardware of the computer in which the above-described series ofprocessing operations are executed by the programs.

In a computer 800 illustrated in FIG. 34, a central processing unit(CPU) 801, a read only memory (ROM) 802, and a random access memory(RAM) 803 are connected to one another through a bus 804.

An input/output interface 810 is also connected to the bus 804. Theinput/output interface 810 is connected to an input unit 811, an outputunit 812, a storage unit 813, a communication unit 814, and a drive 815.

The input unit 811 includes a keyboard, a mouse, a microphone, a touchpanel, an input terminal and the like. The output unit 812 includes, forexample, a display, a speaker, an output terminal and the like. Thestorage unit 813 includes, for example, a hard disk, a RAM disk, anon-volatile memory and the like. The communication unit 814 includes,for example, a network interface. The drive 815 drives a removablemedium 821 such as a magnetic disk, an optical disk, a magneto-opticaldisk, or a semiconductor memory.

In the computer having the configuration described above, the CPU 801may load and execute, for example, the programs stored in the storageunit 813 into the RAM 803 through the input/output interface 810 and thebus 804, thereby performing the series of processing operationsdescribed above. Necessary data and the like for the CPU 801 to executevarious kinds of processing operations are also appropriately stored inthe RAM 803.

The programs executed by the computer (or CPU 801) may be applied bybeing recorded in, for example, the removable medium 821, which may beused as a package medium or the like. In addition, the programs may beprovided through a wired or wireless transmission medium such as a localarea network, the Internet, or digital satellite broadcasting.

In the computer, the programs may be installed into the storage unit 813through the input/output interface 810 in response to the attaching ofthe removable medium 821 to the drive 815. The programs may also bereceived by the communication unit 814 through the wired or wirelesstransmission medium and may be installed into the storage unit 813.Alternatively, the programs may be installed into the ROM 802 or thestorage unit 813 in advance.

Further, the programs to be executed by the computer may be processed inchronological order explained herein, or in a parallel manner, or ondemand such as when they are called.

Further, in this specification, the steps for describing the programs tobe recorded in the recoding medium include not only processingoperations which are performed in chronological order disclosed herein,but also processing operations which are executed in a parallel manneror individually if it is not necessarily performed over time.

In addition, in this specification, a system represents a collection ofa plurality of component elements (devices, modules (components), andlike), and all component elements need not be arranged in the samehousing. Therefore, a plurality of devices accommodated in differenthousings and interconnected through a network is a system; and onedevice in which a plurality of modules is accommodated in a singlehousing is a system as well.

Also, in the above described examples, any configuration described asone device (or one processing unit) may be divided into a plurality ofdevices (or processing units). Conversely, any configuration describedas a plurality of devices (or processing units) may be combined to formone device (or one processing unit). Moreover, any configuration otherthan the configuration described above may be naturally added to theconfiguration of each of the devices (or each of the processing units).Further, a part of the configuration of one device (or one processingunit) may be included in a configuration of other device (or otherprocessing unit) as long as the configuration or operation as the entiresystem is substantially the same.

The preferred embodiments of the present disclosure has been describedin detail with reference to the appended drawings, but the technicalscope of the present disclosure is not limited to the above examples. Itshould be understood by those skilled in the art that variousmodifications or alterations may occur within the scope of the technicalspirit described in claims and they are within the technical scope ofthe present invention.

For example, the present technology can adopt a configuration of cloudcomputing in which one function is cooperatively processed in a sharingfashion by a plurality of devices through a network.

Further, each step described in the above-described flowcharts can beexecuted not only by one device but also by a plurality of devices in asharing fashion.

In addition, if one step includes a plurality of processing operations,the plurality of processing operations included in the one step can beexecuted not only by one device but also by a plurality of devices in asharing fashion.

The image encoding device and the image decoding device according to theabove embodiments can be applicable to various electronic devices suchas a transmitter or a receiver for satellite broadcasting, wiredbroadcasting such as a cable TV, distribution through the Internet anddistribution to a terminal by way of cellular communication, a recordingdevice which records images in a medium such as an optical disk, amagnetic disk and flash memory, and a reproducing device whichreproduces images from these storage media. Four application exampleswill be described below.

7. Seventh Embodiment

[First Application Example: Television Receiver]

FIG. 35 illustrates an example of a schematic configuration of atelevision apparatus to which the above-described embodiment is applied.The television apparatus 900 includes an antenna 901, a tuner 902, ademultiplexer 903, a decoder 904, a video signal processing unit 905, adisplay unit 906, an audio signal processing unit 907, a speaker 908, anexternal interface 909, a control unit 910, a user interface 911, and abus 912.

The tuner 902 extracts a desired channel signal from broadcast signalsreceived through the antenna 901, and demodulates the extracted signal.The tuner 902 outputs the encoded bit stream obtained by demodulation tothe demultiplexer 903. That is, the tuner 902 plays a role of atransmission unit of the television apparatus 900 which receives a codedstream obtained by encoding an image.

The demultiplexer 903 separates a video stream and an audio stream of aviewing target program from the encoded bit stream, and outputs each ofthe separated streams to the decoder 904. Further, the demultiplexer 903extracts auxiliary data such as an electronic program guide (EPG) fromthe encoded bit stream, and supplies the extracted data to the controlunit 910. In addition, the demultiplexer 903 may perform descramblingwhen the encoded bit stream is scrambled.

The decoder 904 decodes the video stream and the audio stream input fromthe demultiplexer 903. Further, the decoder 904 outputs video data,which is generated by a decoding process, to the video signal processingunit 905. Furthermore, the decoder 904 outputs audio data, which isgenerated by a decoding process, to the audio signal processing unit907.

The video signal processing unit 905 reproduces the video data inputfrom the decoder 904, and displays a video image on the display unit906. Further, the video signal processing unit 905 may display on thedisplay unit 906 an application screen supplied through a network.Furthermore, the video signal processing unit 905 may perform anadditional processing operation such as, for example, noise removal onthe video data according to the setting. Further, the video signalprocessing unit 905 may generate an image of a graphical user interface(GUI) image such as, for example, a menu, buttons, a cursor, andsuperimpose the generated image on an output image.

The display unit 906 is driven by a drive signal supplied from the videosignal processing unit 905, and displays a video image or an image on avideo displaying surface of a display device (for example, a liquidcrystal display, a plasma display, or an organic electroluminescencedisplay (GELD) (organic EL display)).

The audio signal processing unit 907 performs a reproducing operationsuch as a D/A conversion and amplification on the audio data input fromthe decoder 904, and outputs an audio from the speaker 908. Further, theaudio signal processing unit 907 may perform an additional processingoperation such as noise removal on the audio data.

The external interface 909 is an interface which is configured toconnect the television apparatus 900 and an external device or thenetwork to each other. For example, a video stream or an audio streamreceived through the external interface 909 may be decoded by thedecoder 904. That is, the external interface 909 also plays a role of atransmission unit in the television apparatus 900 which receives codedstreams of encoded images.

The control unit 910 has a processor such as a CPU and a memory such asRAM and ROM. The memory stores programs to be executed by the CPU,program data, EPG data, and data acquired through the network. Theprogram stored in the memory is read and executed by the CPU at the timeof activation of the television apparatus 900. By executing the program,the CPU controls the operation of the television apparatus 900 accordingto, for example, an operation signal input from the user interface 911.

The user interface 911 is connected to the control unit 910. The userinterface 911 has, for example, buttons and switches which a user usesto operate the television apparatus 900, and a reception unit whichreceives a remote control signal. The user interface 911 detects auser's operation through these components, generates an operationsignal, and outputs the generated operation signal to the control unit910.

The bus 912 is configured to connect the tuner 902, the demultiplexer903, the decoder 904, the video signal processing unit 905, the audiosignal processing unit 907, the external interface 909, and the controlunit 910 to each other.

In the television apparatus 900 having this configuration, the decoder904 has a function of the image decoding device according to the aboveembodiments. Consequently, when decoding of an image in the televisionapparatus 900, it is possible to achieve the suppression of thereduction of the encoding efficiency and to achieve the suppression ofthe deterioration of the image quality due to the encoding/decoding.

[Second Application Example: Mobile Phone]

FIG. 36 illustrates an example of a schematic configuration of acellular phone to which above embodiments are applied. A mobile phone920 includes an antenna 921, a communication unit 922, an audio codec923, a speaker 924, a microphone 925, a camera unit 926, an imageprocessing unit 927, a multiplexing/separating unit 928, arecording/reproducing unit 929, a display unit 930, a control unit 931,an operation unit 932, and a bus 933.

The antenna 921 is connected to the communication unit 922. The speaker924 and the microphone 925 are connected to the audio codec 923. Theoperation unit 932 is connected to the control unit 931. The bus 933 isconfigured to connect the communication unit 922, the audio codec 923,the camera unit 926, the image processing unit 927, themultiplexing/separating unit 928, the recording/reproducing unit 929,the display unit 930, and the control unit 931 to each other.

The mobile phone 920 performs various operations such as transmissionand reception of audio signals, transmission and reception of electronicmail and image data, image capturing, and data recording, in variouskinds of modes such as an audio communication mode, a data communicationmode, a photographing mode, and a video phone mode.

In the audio communication mode, an analog audio signal generated at themicrophone 925 is supplied to the audio codec 923. The audio codec 923converts an analog audio signal into audio data, and performs an A/Dconversion on and compresses the converted audio data. Further, theaudio codec 923 outputs the compressed audio data to the communicationunit 922. The communication unit 922 encodes and modulates the audiodata and generates a transmission signal. Further, the communicationunit 922 transmits the generated transmission signal to a base station(not illustrated) through the antenna 921. Furthermore, thecommunication unit 922 amplifies and performs a frequency conversion ona radio signal received through the antenna 921, and obtains thereceived signal. Still further, the communication unit 922 demodulatesand decodes the received signal, generates audio data, and outputs thegenerated audio data to the audio codec 923. The audio codec 923decompresses the audio data and performs a D/A conversion on the audiodata, and generates an analog audio signal. Further, the audio codec 923supplies the generated audio signal to the speaker 924 and outputs anaudio.

Furthermore, in the data communication mode, for example, the controlunit 931 generates text data which constitutes an electronic mailaccording to a user's operation through the operation unit 932. Further,the control unit 931 displays a text on the display unit 930. Moreover,the control unit 931 generates electronic mail data according totransmission instruction from the user through the operation unit 932,and outputs the generated electronic mail data to the communication unit922. The communication unit 922 encodes and modulates the electronicmail data and generates a transmission signal. Further, thecommunication unit 922 transmits the generated transmission signal to abase station (not illustrated) through the antenna 921. Furthermore, thecommunication unit 922 amplifies and performs a frequency conversion ona radio signal received through the antenna 921, and acquires thereceived signal. Still further, the communication unit 922 demodulatesand decodes the received signal, restores electronic mail data, andoutputs the restored electronic mail data to the control unit 931. Thecontrol unit 931 displays the content of the electronic mail on thedisplay unit 930, and supplies the electronic mail data torecording/reproducing unit 929 to allow the data to be written it in thestorage medium.

The recording/reproducing unit 929 has an arbitrary readable/writablestorage medium. For example, the storage medium may be a built-instorage medium such as RAM or flash memory, and may be a storage mediumwhich is an externally attaching type such as a hard disk, a magneticdisk, a magneto-optical disk, an optical disk, an unallocated spacebitmap (USB) memory, or a memory card.

Further, in the photographing mode, for example, the camera unit 926captures an image of an object, generates image data, and outputs thegenerated image data to the image processing unit 927. The imageprocessing unit 927 encodes the image data input from the camera unit926, and supplies the coded stream to recording/reproducing unit 929 toallow the stream to be written it in the storage medium. Moreover, in animage display mode, the recording/reproducing unit 929 reads the codedstream stored in the storage medium and outputs it to the imageprocessing unit 927. The image processing unit 927 decodes the codedstream input from the recording/reproducing unit 929 and supplies theimage data to the display unit 930 to display the image thereon.

Further, in the video phone mode, for example, themultiplexing/separating unit 928 multiplexes the video stream encoded bythe image processing unit 927 and the audio stream input from the audiocodec 923, and outputs the multiplexed stream to the communication unit922. The communication unit 922 encodes and modulates the stream, andgenerates a transmission signal. Further, the communication unit 922transmits the generated transmission signal to a base station (notillustrated) through the antenna 921. Furthermore, the communicationunit 922 amplifies and performs a frequency conversion on a radio signalreceived through the antenna 921, and acquires the received signal.These transmission signal and received signal may include encoded bitstreams. Further, the communication unit 922 demodulates and decodes thereceived signal, restores the stream, and outputs the restored stream tothe multiplexing/separating unit 928. The multiplexing/separating unit928 separates the video stream and the audio stream from the inputstream, and outputs the video stream to the image processing unit 927and the audio stream to the audio codec 923. The image processing unit927 decodes the video stream and generates the video data. The videodata is supplied to the display unit 930, and the display unit 930displays a series of images. The audio codec 923 decompresses andperforms a D/A conversion on the audio stream, and generates an analogaudio signal. Further, the audio codec 923 supplies the generated audiosignal to the speaker 924 and outputs an audio.

In the mobile phone 920 having the above configuration, the imageprocessing unit 927 has functions of the image encoding device and theimage decoding device according to the above embodiments. Consequently,when encoding and decoding of an image in the mobile phone 920, it ispossible to suppress the reduction of the encoding efficiency and tosuppress the deterioration of the image quality due to theencoding/decoding.

[Third Application Example: Recording and Reproducing Device]

FIG. 37 illustrates an example of a schematic configuration of arecording and reproducing device to which above embodiments are applied.A recording and reproducing device 940 encodes, for example, audio dataand video data of the received broadcast program and records the data inthe recording medium. Further, the recording and reproducing device 940may encode, for example, audio data and video data acquired from anotherdevice and record the data in the recording medium. Furthermore, therecording and reproducing device 940 reproduces data recorded in therecording medium on a monitor and a speaker according to, for example,user's instruction. At this time, the recording and reproducing device940 decodes the audio data and the video data.

The recording and reproducing device 940 includes a tuner 941, anexternal interface 942, an encoder 943, a hard disk drive (HDD) unit944, a disk drive 945, a selector 946, a decoder 947, an on-screendisplay (OSD) 948, a control unit 949, and a user interface 950.

The tuner 941 extracts a desired channel signal from broadcast signalsreceived through an antenna (not illustrated), and demodulates theextracted signal. Further, the tuner 941 outputs an encoded bit stream,which is obtained by demodulation, to the selector 946. That is, thetuner 941 plays a role of a transmission unit in the recording andreproducing device 940.

The external interface 942 is an interface which connects the recordingand reproducing device 940 and an external device or the network to eachother. The external interface 942 may be an IEEE1394 interface, anetwork interface, an USB interface, flash memory interface, and thelike. For example, the video data and the audio data received throughthe external interface 942 are input to the encoder 943. That is, theexternal interface 942 plays a role of a transmission unit in therecording and reproducing device 940.

When the video data and the audio data input from the external interface942 are not encoded, the encoder 943 encodes the video data and theaudio data. Further, the encoder 943 outputs an encoded bit stream tothe selector 946.

The HDD 944 records encoded bit streams obtained by compressing contentdata such as video and audio, various programs, and other data in aninternal hard disk. Further, the HDD 944 reads out these types of datafrom the hard disk at the time of reproduction of a video and an audio.

The disk drive 945 records and reads out data in and from an attachedrecording medium. A recording medium attached to the disk drive 945 maybe, for example, a DVD disk (such as DVD-Video, DVD-RAM, DVD-R, DVD-RW,DVD+R, and DVD+RW) or a Blu-ray (registered trademark) disk.

At the time of video and audio recording, the selector 946 selects anencoded bit stream input from the tuner 941 or the encoder 943 andoutputs the selected encoded bit stream to the HDD 944 or the disk drive945. Further, the selector 946 outputs an encoded bit stream input fromthe HDD 944 or the disk drive 945 to the decoder 947 at the time ofvideo and audio reproduction.

The decoder 947 decodes the encoded bit stream and generates video dataand audio data. Further, the decoder 947 outputs the generated videodata to the OSD 948. Furthermore, the decoder 904 outputs the generatedaudio data to an external speaker.

The OSD 948 reproduces video data input from the decoder 947 anddisplays a video image. Further, the OSD 948 may superimpose a GUI imagesuch as a menu, buttons or a cursor on the video image to be displayed.

The control unit 949 has a processor such as a CPU, and a memory such asRAM and ROM. The memory stores programs to be executed by the CPU, andprogram data. The program stored in the memory is read and executed bythe CPU, for example, at the time of activation of the recording andreproducing device 940. By executing the program, the CPU controls theoperation of the recording and reproducing device 940 according to, forexample, an operation signal input from the user interface 950.

The user interface 950 is connected to the control unit 949. The userinterface 950 has, for example, buttons and switches which are used tooperate the recording and reproducing device 940 by a user, and areception unit which receives a remote control signal. The userinterface 950 detects a user's operation through these components,generates an operation signal, and outputs the generated operationsignal to the control unit 949.

In the recording and reproducing device 940 having the aboveconfiguration, the encoder 943 has a function of the image encodingdevice according to the above embodiments. Further, the decoder 947 hasa function of the image decoding device according to the aboveembodiments. Consequently, when encoding and decoding of an image in therecording and reproducing device 940, it is possible to suppress thereduction of the encoding efficiency and to suppress the deteriorationof the image quality due to the encoding/decoding.

[Fourth Application Example: Imaging Device]

FIG. 38 illustrates an example of a schematic configuration of animaging device to which the above embodiments are applied. An imagingdevice 960 captures an image of an object, generates an image, encodesimage data, and records the image data in a recording medium.

The imaging device 960 includes an optical block 961, an imaging unit962, a signal processing unit 963, an image processing unit 964, adisplay unit 965, an external interface 966, a memory 967, a media drive968, an OSD 969, a control unit 970, a user interface 971, and a bus972.

The optical block 961 is connected to an imaging unit 962. The imagingunit 962 is connected to the signal processing unit 963. The displayunit 965 is connected to the image processing unit 964. The userinterface 971 is connected to the control unit 970. The bus 972 isconfigured to connect the image processing unit 964, the externalinterface 966, the memory 967, the media drive 968, the OSD 969, and thecontrol unit 970 to each other.

The optical block 961 has a focus lens, a diaphragm, and the like. Theoptical block 961 forms an optical image of an object on the imagingsurface of the imaging unit 962. The imaging unit 962 has an imagesensor such as a charge coupled device (CCD) or a complementary metaloxide semiconductor (CMOS) and converts the optical image formed on theimaging surface into an image signal as an electric signal byphotoelectric conversion. Further, the imaging unit 962 outputs theimage signal to the signal processing unit 963.

The signal processing unit 963 performs various kinds of camera signalprocessing operations such as a knee correction, a gamma correction, anda color correction on the image signal input from the imaging unit 962.The signal processing unit 963 outputs image data, in which the camerasignal processing operation is performed, to the image processing unit964.

The image processing unit 964 encodes the image data input from thesignal processing unit 963 and generates the coded data. Further, theimage processing unit 964 outputs the generated coded data to theexternal interface 966 or the media drive 968. Furthermore, the imageprocessing unit 964 decodes the coded data input from the externalinterface 966 or the media drive 968 and generates image data. Stillfurther, the image processing unit 964 outputs the generated image datato the display unit 965. Moreover, the image processing unit 964 mayoutput the image data input from the signal processing unit 963 to thedisplay unit 965 and display an image. Further, the image processingunit 964 may superimpose displaying data acquired from the OSD 969, onthe image to be output to the display unit 965.

The OSD 969 generates a GUI image such as a menu, buttons or a cursor,and outputs the generated image to the image processing unit 964.

The external interface 966 is configured as, for example, a USBinput/output terminal. The external interface 966 connects the imagingdevice 960 and a printer to each other, for example, at the time ofprinting of an image. Further, the external interface 966 is connectedwith a drive if necessary. The drive is attached with a removable mediumsuch as a magnetic disk or an optical disk, and the program read fromthe removable medium can be installed in the imaging device 960.Further, the external interface 966 may be configured as a networkinterface connected to a network such as a LAN or the Internet. That is,the external interface 966 plays a role of a transmission unit in theimaging device 960.

A recording medium attached to the media drive 968 may be areadable/rewritable removable medium such as a magnetic disk, amagneto-optical disk, an optical disk, or a semiconductor memory.Further, a recording medium is fixedly attached to the media drive 968,and, for example, a non-portable storage unit such as a built-in harddisk drive or a solid state drive (SSD) may be configured.

The control unit 970 has a processor such as a CPU, and a memory such asRAM and ROM. The memory stores programs to be executed by the CPU, andprogram data. The program stored in the memory is read and executed bythe CPU, for example, at the time of activation of the imaging device960. By executing the program, the CPU controls the operation of theimaging device 960 according to, for example, an operation signal inputfrom the user interface 971.

The user interface 971 is connected to the control unit 970. The userinterface 971 has, for example, buttons and switches which are used tooperate the imaging device 960 by a user. The user interface 971 detectsa user's operation through these components, generates an operationsignal, and outputs the generated operation signal to the control unit970.

In the imaging device 960 having the above configuration, the imageprocessing unit 964 has functions of the image encoding device and theimage decoding device according to the above embodiments. Consequently,when encoding and decoding of an image in the imaging device 960, it ispossible to suppress the reduction of the encoding efficiency and tosuppress the deterioration of the image quality due to theencoding/decoding.

8. Eighth Embodiment

[Application Example of Scalable Encoding: First System]

Next, a specific example of use of scalable coded data which has beensubjected to scalable encoding (or hierarchical (image) encoding) willbe described. The scalable encoding may be used for, for example, aselection of data to be transmitted, as in an example illustrated inFIG. 39.

In a data transmission system 1000 illustrated in FIG. 39, adistribution server 1002 reads out scalable coded data stored in ascalable coded data storage unit 1001 and distributes the scalable codeddata to terminal devices, such as a personal computer 1004, an AV device1005, a tablet device 1006, and a mobile phone 1007, through a network1003.

At this time, the distribution server 1002 selects coded data havingappropriate quality in accordance with the performance of the terminaldevice and the communication environment, and transmits the selectedcoded data. Even if the distribution server 1002 transmits data havingquality higher than necessary, the terminal device may not necessarilyobtain a high-quality image, and may cause delay or overflow. Inaddition, such data may occupy communication bandwidth more thannecessary, or may increase the load on the terminal device more thannecessary. Conversely, even if the distribution server 1002 transmitsdata having quality lower than necessary, the terminal device may notobtain an image with a sufficient quality in the device. Thus, thedistribution server 1002 reads out the scalable coded data stored in thescalable coded data storage unit 1001, if necessary, as coded datahaving quality appropriate for certain conditions such as theperformance of the terminal device and communication environment, andtransmits the read coded data.

For example, the scalable coded data storage unit 1001 stores scalablecoded data (BL+EL) 1011 which has been subjected to scalable encoding.The scalable coded data (BL+EL) 1011 is coded data including both a baselayer and an enhancement layer and is data which is decoded to obtainboth base layer images and enhancement layer images.

The distribution server 1002 selects an appropriate layer in accordancewith the performance of the terminal device which transmits data and thecommunication environment, and reads out the data of the layer. Forexample, the distribution server 1002 reads out high-quality scalablecoded data (BL+EL) 1011 from the scalable coded data storage unit 1001and transmits the read scalable coded data as it is to the personalcomputer 1004 or the tablet device 1006 which has high processingcapabilities. In contrast, for example, the distribution server 1002extracts the data of the base layer from the scalable coded data (BL+EL)1011 and transmits the extracted data of the base layer to the AV device1005 or the mobile phone 1007 which has low processing capabilities, asscalable coded data (BL) 1012 having the same content as the scalablecoded data (BL+EL) 1011 and having lower quality than the scalable codeddata (BL+EL) 1011.

In this manner, the use of scalable coded data can facilitate theadjustment of the amount of data, thereby suppressing the occurrence ofdelay or overflow and suppressing an unnecessary increase in the load onthe terminal device or the communication medium. In addition, since thescalable coded data (BL+EL) 1011 has reduced redundancy between layers,it is possible to reduce the amount of data compared to a case of havingindividually coded data of the respective layers. Therefore, the storagearea of the scalable coded data storage unit 1001 can be moreefficiently utilized.

Further, since various devices such as the personal computer 1004 andthe mobile phone 1007 may be applied to the terminal device, hardwareperformance of the terminal device may be device-dependent. In addition,since various applications are also executable by the terminal device,software capabilities of the applications may vary. Furthermore, thenetwork 1003 serving as a communication medium may be adopted as anycommunication line network which can be wired, wireless, or both, suchas the Internet or a local area network (LAN), and have various datatransmission capabilities. Moreover, such performance and capabilitiesmay vary with other communication and the like.

Therefore, before the start of transmission of data, the distributionserver 1002 may communicate with a terminal device to which the data isto be transmitted, and may obtain information concerning thecapabilities of the terminal device, such as the hardware performance ofthe terminal device or the performance of application (software)executed by the terminal device, and also information concerning thecommunication environment, such as the available bandwidth of thenetwork 1003. Then, the distribution server 1002 may select anappropriate layer on the basis of the obtained information.

The extraction of a layer may be performed by a terminal device. Forexample, the personal computer 1004 may decode the transmitted scalablecoded data (BL+EL) 1011 and display a base layer image or an enhancementlayer image. Alternatively, for example, the personal computer 1004 mayextract the scalable coded data (BL) 1012 of the base layer from thetransmitted scalable coded data (BL+EL) 1011, store the extractedscalable coded data or transmit the data to another device, or decodethe data to display the base layer image.

Naturally, the number of scalable coded data storage units 1001, thenumber of distribution servers 1002, the number of networks 1003, andthe number of terminal devices are arbitrary. In addition, while anexample in which the distribution server 1002 transmits data to theterminal device is described above, application examples are not limitedthereto. The data transmission system 1000 can be applied to any systemas long as the system selects and transmits an appropriate layer, whentransmitting coded data which has been subjected to the scalableencoding to the terminal device, in accordance with certain conditionssuch as the capabilities of the terminal device and the communicationenvironment.

The same effects as those described above with reference to FIGS. 1 to31 can be obtained by applying the same technology as in the applicationto the hierarchical encoding/hierarchical decoding described above withreference to FIGS. 1 to 31 in the data transmission system 1000illustrated in FIG. 39.

[Application Example of Scalable Encoding: Second System]

Scalable encoding may also be used for transmission through a pluralityof communication media, as in an example illustrated in, for example,FIG. 40.

In a data transmission system 1100 illustrated in FIG. 40, abroadcasting station 1101 transmits scalable coded data (BL) 1121 of abase layer through terrestrial broadcasting 1111. In addition, thebroadcasting station 1101 transmits scalable coded data (EL) 1122 of theenhancement layer through an arbitrary network 1112, which is configuredby a wired communication network, a wireless communication network, orboth the wired and wireless communication networks (for example, thedata is packetized and transmitted).

A terminal device 1102 has a function of receiving the terrestrialbroadcasting 1111 which is broadcasted by the broadcasting station 1101and receives the scalable coded data (BL) 1121 of the base layertransmitted through the terrestrial broadcasting 1111. The terminaldevice 1102 further has a communication function for performingcommunication through the network 1112 and receives the scalable codeddata (EL) 1122 of the enhancement layer transmitted through the network1112.

The terminal device 1102, for example, in accordance with a user'sinstruction or the like, acquires an image of the base layer by decodingthe scalable coded data (BL) 1121 of the base layer that is acquiredthrough the terrestrial broadcasting 1111, stores the acquired scalablecoded data, or transmits the acquired data to another device.

In addition, the terminal device 1102, for example, in accordance with auser's instruction, composes the scalable coded data (BL) 1121 of thebase layer that is acquired through the terrestrial broadcasting 1111and the scalable coded data (EL) 1122 of the enhancement layer that isacquired through the network 1112 so as to acquire the scalable codeddata (BL+EL), decodes the scalable coded data so as to acquire or storean image of the enhancement layer, or transmits the scalable coded datato another device.

As described above, the scalable coded data may be transmitted through,for example, a communication medium different for each layer. Thus, theload can be distributed, and the occurrence of a delay or an overflowcan be suppressed.

In addition, depending on the situation, the communication medium thatis used for the transmission may be configured to be selectable for eachlayer. For example, it may be configured such that the scalable codeddata (BL) 1121 of the base layer of which the data amount is relativelylarge is transmitted through a communication medium having a widebandwidth, and the scalable coded data (EL) 1122 of the enhancementlayer of which the data amount is relatively small is transmittedthrough a communication medium having a narrow bandwidth. In addition,for example, the communication medium through which the scalable codeddata (EL) 1122 of the enhancement layer is transmitted may be configuredto be switched between the network 1112 and the terrestrial broadcasting1111 in accordance with the usable bandwidth of the network 1112. Thissimilarly applies to the data of an arbitrary layer.

By controlling as such, an increase in the load for the datatransmission can be further suppressed.

Here, the number of layers is arbitrary, and the number of communicationmedia used for the transmission is also arbitrary. In addition, thenumber of the terminal devices 1102 that are the data deliverydestination is arbitrary as well. Furthermore, while, in the descriptionpresented above, the example has been described in which broadcasting isperformed from the broadcasting station 1101, the example of the use isnot limited thereto. The data transmission system 1100 may be applied toan arbitrary system as long as the system divides coded data which iscoded in a scalable coded manner into a plurality of parts in units oflayers and transmits the divided data through a plurality of lines.

Then, even in the data transmission system 1100 illustrated in FIG. 40,it is possible to obtain effects similar to those described above withreference to FIGS. 1 to 31 by applying the present technology in thesame manner as the application to the hierarchical encode/hierarchicaldecoding described above with reference to FIGS. 1 to 31.

[Application Example of Scalable Encoding: Third System]

Scalable encoding may also be used for storing coded data, as in anexample illustrated in, for example, FIG. 41.

In an imaging system 1200 illustrated in FIG. 41, an imaging device 1201performs scalable encoding of image data that is acquired by imaging asubject 1211 and supplies resultant image data to a scalable coded datastorage device 1202 as scalable coded data (BL+EL) 1221.

The scalable coded data storage device 1202 stores the scalable codeddata (BL+EL) 1221 supplied from the imaging device 1201 with qualityaccording to the situation. For example, in the case of a normal time,the scalable coded data storage device 1202 extracts data of the baselayer from the scalable coded data (BL+EL) 1221 and stores the extracteddata of the base layer as scalable coded data (BL) 1222 of the baselayer having low quality and a small amount of data. In contrast, forexample, in the case of an attention time, the scalable coded datastorage device 1202 stores the scalable coded data (BL+EL) 1221 having ahigh quality and a large amount of data as it is.

In this way, the scalable coded data storage device 1202 can store animage with high image quality only as necessary. Accordingly, while adecrease in the value of the image due to deterioration of the imagequality is suppressed, an increase in the amount of data can besuppressed, whereby the use efficiency of the storage area can beimproved.

For example, the imaging device 1201 may be a monitoring camera. When anobject to be monitored (for example, an intruder) is not visible in acaptured image (in the case of the normal time), it is likely that thecontent of the captured image is not important. Thus, a decrease in theamount of data is prioritized, and the image data (scalable coded data)of the image is stored with low quality. In contrast, when an object tobe monitored is visible as the subject 1211 in a captured image (in thecase of the attention time), it is likely that the captured image hasimportant content. Thus, image quality is prioritized, and the imagedata (scalable coded data) of the image is stored with a high quality.

Either the normal time or the attention time may be determined by, forexample, the scalable coded data storage device 1202 by analyzing theimage. In addition, the imaging device 1201 may determine the normaltime or the attention time and may transmit the determination result tothe scalable coded data storage device 1202.

Here, the determination criterion of either the normal time or theattention time may be arbitrary, and the image which is considered to beas the determination criterion may have any content. Naturally,conditions other than the content of the image may be used as thedetermination criterion. For example, the condition for determinationmay be changed in accordance with the size, the waveform, or the like ofrecorded voice, may be changed for every predetermined time, or may bechanged in accordance with an instruction which is supplied from theoutside such as a user's instruction.

In addition, while the description has been given to an example ofchanging between two states, namely, normal time and attention time, thenumber of states is arbitrary, and the state change may be made amongthree or more states, such as a normal time, a low-attention time, amiddle-attention time, and a high-attention time. However, the upperlimit number of states to be changed depends on the number of layers ofscalable coded data.

Further, the imaging device 1201 may determine the number of layers ofscalable encoding in accordance with the states. For example, in thenormal time, the imaging device 1201 may generate scalable coded data(BL) 1222 of the base layer having a low quality and a small amount ofdata and supply the generated scalable coded data (BL) 1222 to thescalable coded data storage device 1202. Further, for example, in theattention time, the imaging device 1201 may generate scalable coded data(BL+EL) 1221 of the base layer having a high quality and a large amountof data and supply the generated scalable coded data (BL+EL) 1221 to thescalable coded data storage device 1202.

In the above description, while the monitoring camera has been describedas an example, the imaging system 1200 may be used in any application,and the application is not limited to the monitoring camera.

Then, even in the imaging system 1200 illustrated in FIG. 41, it ispossible to obtain effects similar to those described above withreference to FIGS. 1 to 31 by applying the present technology in thesame manner as the application to the hierarchical encoding/hierarchicaldecoding described above with reference to FIGS. 1 to 31.

Further, the present technology is used by selecting appropriate data,in a segment unit, from a plurality kinds of coded data having differentresolutions or the like which are prepared in advance and can be alsoapplied to HTTP streaming such as, for example, MPEG/DASH. That is,information on the encoding or decoding can be shared between theplurality kinds of coded data.

9. Ninth Embodiment Other Examples

While, in the description presented above, the examples of the devices,the systems, and the like to which the present technology is appliedhave been described, the present technology is not limited thereto.Thus, the present technology may be applied as all the configurationsmounted to such a device or devices configuring such a system, forexample, a processor as a system LSI (Large Scale Integration) or thelike, a module that uses a plurality of processors or the like, a unitthat uses a plurality of modules or the like, or a set or the like (inother words, a part of the configuration of the device) acquired byadding other functions to the unit.

[Video Set]

An example of a case where the present technology is applied as a setwill be described with reference to FIG. 42. FIG. 42 illustrates anexample of the schematic configuration of a video set to which thepresent technology is applied.

Recently, the implementation of multiple functions of an electronicdevice is in progress, and, in the development or the manufacturingthereof, in a case where a part of the configuration is provided forsale, provision, or the like, there are not only a case where theconfiguration having one function is applied but also a case where oneset having a plurality of functions, which is acquired by combining aplurality of configurations having relating function, is applied, whichhas commonly been seen.

The video set 1300 illustrated in FIG. 42 has such a multi-functionconfiguration and is acquired by combining a device having a functionrelating to image encoding or image decoding (either one or both) withdevices having other functions relating to the function.

As illustrated in FIG. 42, the video set 1300 includes a module groupthat includes a video module 1311, an external memory 1312, a powermanagement module 1313, a front end module 1314, and the like anddevices having related functions of a connectivity 1321, a camera 1322,a sensor 1323, and the like.

A module is formed as a component having a function having unity byarranging several component functions relating to each other together.While a specific physical configuration is arbitrary, for example, amodule acquired by arranging a plurality of processors each having afunction, an electronic circuit component such as a resistor or acapacitor, and other devices or the like on a wiring board or the likeso as to be integrated together may be considered. In addition, it maybe considered to form a new module by combining a module with othermodules, processors, and the like.

In the example illustrated in FIG. 42, the video module 1311 is acquiredby combining configurations having functions relating to imageprocessing and includes: an application processor; a video processor; abroadband modem 1333; and an RF module 1334.

The processor is acquired by integrating a configuration having apredetermined function on a semiconductor chip as SoC (System On a Chip)and, for example, there is also the processor that is called a systemLSI (Large Scale Integration) or the like. The configuration having thepredetermined function may be a logic circuit (hardware configuration),a configuration including a CPU, a ROM, a RAM, and the like and aprogram (software configuration) executed using them, or a configurationcombining both the configurations described above. For example, it maybe configured such that the processor includes logic circuits, a CPU, aROM, a RAM, and the like, some functions are realized by the logiccircuits (hardware configuration), and the other functions are realizedby a program (software configuration) executed by the CPU.

The application processor 1331 illustrated in FIG. 42 is a processorthat executes an application relating to image processing. In order torealize predetermined functions, the application executed by theapplication processor 1331 may not only perform a calculation processbut also control the configurations of the inside and the outside of thevideo module 1311 such as the video processor 1332 as is necessary.

The video processor 1332 is a processor that has a function relating toimage encoding and image decoding (either one or both).

The broadband modem 1333 converts data (digital signal) transmitted bywired or wireless (or wired and wireless) broadband communicationperformed through a broadband line such as the Internet or a publictelephone network into an analog signal through digital modulation orthe like or demodulates the analog signal received by the broadbandcommunication so as to be converted into data (digital signal). Forexample, the broadband modem 1333 processes arbitrary information suchas image data processed by the video processor 1332, a stream in whichthe image data is encoded, an application program, and setting data.

The RF module 1334 is a module that performs frequency conversion,modulation/demodulation, amplification, a filter process, and the likefor an RF (Radio Frequency) signal that is transmitted/received throughan antenna. For example, the RF module 1334 generates an RF signal byperforming frequency conversion and the like for a baseband signalgenerated by the broadband modem 1333. In addition, for example, the RFmodule 1334 generates a baseband signal by performing frequencyconversion and the like for an RF signal received through the front endmodule 1314.

In addition, as denoted by a dotted line 1341 in FIG. 42, theapplication processor 1331 and the video processor 1332 may beintegrated so as to be configured as one processor.

The external memory 1312 is a module that is disposed outside the videomodule 1311 and includes a storage device used by the video module 1311.The storage device of the external memory 1312 may be realized by anyphysical configuration. However, generally, since the storage device isfrequently used for storing data having a large capacity such as imagedata configured in units of frames, the storage device is preferablyrealized by a semiconductor memory that has a large capacity atrelatively low cost such as a DRAM (Dynamic Random Access Memory).

The power management module 1313 manages and controls the supply ofpower to the video module 1311 (each configuration within the videomodule 1311).

The front end module 1314 is a module that provides a front end function(a transmission/reception-end circuit on the antenna side) for the RFmodule 1334. As illustrated in FIG. 42, the front end module 1314, forexample, includes an antenna unit 1351, a filter 1352, and anamplification unit 1353.

The antenna unit 1351 includes an antenna that transmits/receives awireless signal and a peripheral configuration thereof. The antenna unit1351 transmits a signal supplied from the amplification unit 1353 as awireless signal and supplies a received wireless signal to the filter1352 as an electric signal (RF signal). The filter 1352 performs afilter process and the like for the RF signal received through theantenna unit 1351 and supplies the RF signal after the process to the RFmodule 1334. The amplification unit 1353 amplifies the RF signalsupplied from the RF module 1334 and supplies the amplified RF signal tothe antenna unit 1351.

The connectivity 1321 is a module that has a function relating to aconnection to the outside. The physical configuration of theconnectivity 1321 is arbitrary. For example, the connectivity 1321includes a configuration having a communication function other than thecommunication specification to which the broadband modem 1333corresponds, external input/output terminals, and the like.

For example, the connectivity 1321 may be configured to include a modulehaving communication functions that are compliant with radiocommunication specifications such as Bluetooth (registered trademark),IEEE 802.11 (for example, Wi-Fi (Wireless Fidelity; registeredtrademark)), NFC (Near Field Communication), and IrDA (InfraRed DataAssociation) and an antenna that transmits/receives signals that arecompliant with the specifications. In addition, for example, theconnectivity 1321 may be configured to include a module havingcommunication functions that are compliant with wired communicationspecifications such as USB (Universal Serial Bus) and HDMI (registeredtrademark) (High-Definition Multimedia Interface) and terminals that arecompliant with the specifications. Furthermore, for example, theconnectivity 1321 may be configured to have an additional data (signal)transmission function and the like of analog input/output terminals orthe like.

In addition, the connectivity 1321 may be configured to include a devicethat is the transmission destination of data (signal). For example, theconnectivity 1321 may be configured to include a drive (including notonly a drive of a removable medium but also a hard disk, an SSD (SolidState Drive), a NAS (Network Attached Storage), and the like) thatperforms data reading or data writing for a recoding medium such as amagnetic disk, an optical disc, a magneto-optical disk, or asemiconductor memory. Furthermore, the connectivity 1321 may beconfigured to include an output device (a monitor, a speaker, or thelike) of an image or an audio.

The camera 1322 is a module that has a function for acquiring image dataof a subject by imaging the subject. The image data acquired by animaging process performed by the camera 1322, for example, is suppliedto the video processor 1332 and is coded.

The sensor 1323 is a module that has the function of an arbitrary sensorsuch as an audio sensor, an ultrasonic sensor, an optical sensor, anilluminance sensor, an infrared sensor, an image sensor, a rotationsensor, an angle sensor, an angular velocity sensor, a speed sensor, anacceleration sensor, a tilt sensor, a magnetic identification sensor, animpact sensor, or a temperature sensor. Data that is detected by thesensor 1323, for example is supplied to the application processor 1331and is used by the application and the like.

In the description presented above, each configuration described as amodule may be realized by a processor, and each configuration describedas a processor may be realized by a module.

As will be described later, the present technology may be applied to thevideo processor 1332 of the video set 1300 having the configuration asdescribed above. Accordingly, the video set 1300 may be configured as aset to which the present technology is applied.

[Configuration Example of Video Processor]

FIG. 43 illustrates an example of the schematic configuration of thevideo processor 1332 (FIG. 42) to which the present technology isapplied.

In the example illustrated in FIG. 43, the video processor 1332 has afunction of receiving an input of a video signal and an audio signal andencoding the received signals in accordance with a predetermined systemand a function of decoding coded video data and coded audio data andreproducing and outputting a video signal and an audio signal.

As illustrated in FIG. 43, the video processor 1332 includes: a videoinput processing unit 1401; a first image enlargement/reduction unit1402; a second image enlargement/reduction unit 1403; a video outputprocessing unit 1404; a frame memory 1405; and a memory control unit1406. In addition, the video processor 1332 includes: anencoding/decoding engine 1407; video ES (Elementary Stream) buffers1408A and 1408B, and audio ES buffers 1409A and 1409B. In addition, thevideo processor 1332 includes: an audio encoder 1410; an audio decoder1411; a multiplexer (MUX) 1412; a demultiplexer (DMUX) 1413; and astream buffer 1414.

The video input processing unit 1401, for example, acquires a videosignal input from the connectivity 1321 (FIG. 42) or the like andconverts the acquired video signal into digital image data. The firstimage enlargement/reduction unit 1402 performs format conversion and animage enlargement/reduction process for the image data. The second imageenlargement/reduction unit 1403, for the image data, performs an imageenlargement/reduction process in accordance with a format of the outputdestination through the video output processing unit 1404 or performsformat conversion and an image enlargement/reduction process, which aresimilar to those of the first image enlargement/reduction unit 1402, andthe like. The video output processing unit 1404 performs formatconversion, conversion into an analog signal, and the like for the imagedata and outputs a resultant signal, for example, to the connectivity1321 (FIG. 42) or the like as a reproduced video signal.

The frame memory 1405 is a memory for image data that is shared by thevideo input processing unit 1401, the first image enlargement/reductionunit 1402, the second image enlargement/reduction unit 1403, the videooutput processing unit 1404, and the encoding/decoding engine 1407. Theframe memory 1405 is realized as a semiconductor memory such as a DRAM.

The memory control unit 1406 receives a synchronization signal suppliedfrom the encoding/decoding engine 1407 and controls an access to theframe memory 1405 for writing/reading in accordance with an accessschedule for the frame memory 1405 that is written into an accessmanagement table 1406A. The access management table 1406A is updated bythe memory control unit 1406 in accordance with the process that isperformed by the encoding/decoding engine 1407, the first imageenlargement/reduction unit 1402, the second image enlargement/reductionunit 1403, and the like.

The encoding/decoding engine 1407 performs an encoding process of imagedata and performs a decoding process of a video stream that is a dataacquired by encoding the image data. For example, the encoding/decodingengine 1407 encodes the image data read from the frame memory 1405 andsequentially writes the read image data into the video ES buffer 1408Aas a video stream. In addition, for example, the encoding/decodingengine 1407 sequentially reads the video stream from the video ES buffer1408B, decodes the read video stream, and sequentially writes thedecoded video stream into the frame memory 1405 as image data. Theencoding/decoding engine 1407 uses the frame memory 1405 as a work areain such encoding or decoding processes. In addition, theencoding/decoding engine 1407, for example, at the timing of startingthe process of each macroblock, outputs a synchronization signal to thememory control unit 1406.

The video ES buffer 1408A buffers the video stream generated by theencoding/decoding engine 1407 and supplies the video stream to themultiplexer (MUX) 1412. The video ES buffer 1408B buffers the videostream supplied from the demultiplexer (DMUX) 1413 and supplies thevideo stream to the encoding/decoding engine 1407.

The audio ES buffer 1409A buffers the audio stream generated by theaudio encoder 1410 and supplies the audio stream to the multiplexer(MUX) 1412. The audio ES buffer 1409B buffers the audio stream suppliedfrom the demultiplexer (DMUX) 1413 and supplies the audio stream to theaudio decoder 1411.

The audio encoder 1410 digital exchanges an audio signal, for example,input from the connectivity 1321 (FIG. 42) or the like, and for example,encodes the digital signal in accordance with a predetermined systemsuch as an MPEG audio system or an AC3 (AudioCode number 3) system. Theaudio encoder 1410 sequentially writes audio streams that are dataacquired by encoding the audio signals into the audio ES buffer 1409A.The audio decoder 1411 decodes the audio stream supplied from the audioES buffer 1409B, performs conversion of the decoded audio stream, forexample, into an analog signal and the like, and supplies the convertedsignal, for example, to the connectivity 1321 (FIG. 42) and the like asa reproduced audio signal.

The multiplexer (MUX) 1412 multiplexes the video stream and the audiostream. The multiplexing method (in other words, the format of a bitstream generated by the multiplexing) is arbitrary. In addition, at thetime of multiplexing, the multiplexer (MUX) 1412 may add predeterminedheader information or the like to the bit stream. In other words, themultiplexer (MUX) 1412 can convert the format of the stream through themultiplexing process. For example, by multiplexing the video stream andthe audio stream, the multiplexer (MUX) 1412 converts the video streamand the audio stream into a transport stream that is a bit stream havinga format for transmission. In addition, for example, by multiplexing thevideo stream and the audio stream, the multiplexer (MUX) 1412 convertsthe video stream and the audio stream into data (file data) having aformat for recording.

The demultiplexer (DMUX) 1413 demultiplexes the bit stream in which thevideo stream and the audio stream are multiplexed using a methodcorresponding to the multiplexing process performed by the multiplexer(MUX) 1412. In other words, the demultiplexer (DMUX) 1413 extracts avideo stream and an audio stream from the bitstream read from the streambuffer 1414 (the video stream and the audio stream are separated). Inother words, the demultiplexer (DMUX) 1413 can convert (inverseconversion of the conversion performed by the multiplexer (MUX) 1412)the format of the stream through the demultiplexing process. Forexample, the demultiplexer (DMUX) 1413 acquires the transport stream,for example, supplied from the connectivity 1321 (FIG. 42), thebroadband modem 1333, or the like (FIG. 42) through the stream buffer1414 and demultiplexes the acquired transport stream, thereby convertingthe transport stream into a video stream and an audio stream. Inaddition, for example, the demultiplexer (DMUX) 1413 acquires file dataread from various recording media, for example, by the connectivity 1321(FIG. 42) through the stream buffer 1414 and demultiplexes the acquiredfile data, thereby converting the file data into a video stream and anaudio stream.

The stream buffer 1414 buffers the bit stream. For example, the streambuffer 1414 buffers the transport stream supplied from the multiplexer(MUX) 1412 and supplies the transport stream, for example, to theconnectivity 1321 (FIG. 42), the broadband modem 1333 (FIG. 42), and thelike at predetermined timing or based on a request transmitted from theoutside.

In addition, for example, the stream buffer 1414 buffers the file datasupplied from the multiplexer (MUX) 1412 and supplies the file data, forexample, to the connectivity 1321 (FIG. 42) and the like atpredetermined timing or based on a request transmitted from the outside.

Furthermore, the stream buffer 1414 buffers the transport streamacquired, for example, through the connectivity 1321 (FIG. 42), thebroadband modem 1333 (FIG. 42), or the like and supplies the transportstream to the demultiplexer (DMUX) 1413 at predetermined timing or basedon a request from the outside, and the like.

In addition, the stream buffer 1414 buffers the file data read fromvarious recording media, for example, by the connectivity 1321 (FIG. 42)or the like and supplies the file data to the demultiplexer (DMUX) 1413at predetermined timing or based on a request from the outside or thelike.

Next, an example of the operation of the video processor 1332 havingsuch a configuration will be described. For example, a video signalinput to the video processor 1332 from the connectivity 1321 (FIG. 42)or the like is converted into digital image data according to apredetermined system such as the 4:2:2Y/Cb/Cr system by the video inputprocessing unit 1401 and is sequentially written into the frame memory1405. This digital image data is read by the first imageenlargement/reduction unit 1402 or the second imageenlargement/reduction unit 1403, and a format conversion into apredetermined system such as the 4:2:0Y/Cb/Cr system or the like and theenlargement/reduction process is performed for the digital image data,and the processed digital image data is written again into the framememory 1405. This image data is coded by the encoding/decoding engine1407 and is written into the video ES buffer 1408A as a video stream.

In addition, the audio signal input from the connectivity 1321 (FIG. 42)or the like to the video processor 1332 is coded by the audio encoder1410 and is written into the audio ES buffer 1409A as an audio stream.

The video stream stored in the video ES buffer 1408A and the audiostream stored in the audio ES buffer 1409A are read by the multiplexer(MUX) 1412, are multiplexed, and are converted into a transport stream,file data, or the like. The transport stream generated by themultiplexer (MUX) 1412 is buffered into the stream buffer 1414 and thenis output to the external network, for example, through the connectivity1321 (FIG. 42), the broadband modem 1333 (FIG. 42), or the like. Inaddition, the file data generated by the multiplexer (MUX) 1412 isbuffered into the stream buffer 1414, then is output, for example, tothe connectivity 1321 (FIG. 42) or the like, and is recorded in variousrecording media.

In addition, the transport stream that is input from the externalnetwork to the video processor 1332, for example, through theconnectivity 1321 (FIG. 42), the broadband modem 1333 (FIG. 42), or thelike is buffered into the stream buffer 1414 and then is demultiplexedby the demultiplexer (DMUX) 1413. In addition, the file data that isread from those various recording media, for example, by theconnectivity 1321 (FIG. 42) or the like and is input to the videoprocessor 1332 is buffered into the stream buffer 1414 and then isdemultiplexed by the demultiplexer (DMUX) 1413. In other words, thetransport stream or the file data input to the video processor 1332 isseparated into a video stream and an audio stream by the demultiplexer(DMUX) 1413.

The audio stream is supplied to the audio decoder 1411 through the audioES buffer 1409B and is decoded, and the audio signal is reproduced. Inaddition, the video stream is written into the video ES buffer 1408B,then is sequentially read by the encoding/decoding engine 1407, isdecoded, and is written into the frame memory 1405. The decoded imagedata is enlarged or reduced by the second image enlargement/reductionunit 1403 and is written into the frame memory 1405. Then, the decodedimage data is read by the video output processing unit 1404, has theformat converted into a predetermined system such as the 4:2:2Y/Cb/Crsystem, and is further converted into an analog signal, and the videosignal is reproduced and output.

In a case where the present technology is applied to the video processor1332 configured as such, the present technology according to eachembodiment described above may be applied to the encoding/decodingengine 1407. In other words, for example, the encoding/decoding engine1407 may be configured to have the functions of the image encodingdevice 100 (FIG. 1) according to the first embodiment or the imagedecoding device 200 (FIG. 19) according to the second embodiment. Byconfiguring as such, the video processor 1332 can acquire the sameadvantages as those described above with reference to FIGS. 1 to 31.

In addition, in the encoding/decoding engine 1407, the presenttechnology (in other words, the functions of the image encoding deviceand the image decoding device according to each embodiment describedabove) may be realized by hardware such as logic circuits, may berealized by software such as a built-in program, or may be realized byboth the hardware and the software.

[Another Configuration Example of Video Processor]

FIG. 44 is a diagram that illustrates another example of the schematicconfiguration of the video processor 1332 (FIG. 42) to which the presenttechnology is applied. In the case of the example illustrated in FIG.44, the video processor 1332 has a function of encoding/decoding thevideo data in accordance with a predetermined system.

More specifically, as illustrated in FIG. 44, the video processor 1332includes: a control unit 1511; a display interface 1512; a displayengine 1513; an image processing engine 1514; and an internal memory1515. In addition, the video processor 1332 includes: a codec engine1516; a memory interface 1517; a multiplexer/demultiplexer (MUX DMUX)1518; a network interface 1519; and a video interface 1520.

The control unit 1511 controls the operations of processing unitsarranged within the video processor 1332 such as the display interface1512, the display engine 1513, the image processing engine 1514, and thecodec engine 1516.

As illustrated in FIG. 44, the control unit 1511, for example, includesa main CPU 1531, a sub CPU 1532, and a system controller 1533. The mainCPU 1531 executes a program that is used for controlling the operationof each processing unit disposed within the video processor 1332. Themain CPU 1531 generates a control signal in accordance with the programor the like and supplies the control signal to each processing unit (inother words, controls the operation of each processing unit). The subCPU 1532 achieves an auxiliary role for the main CPU 1531. For example,the sub CPU 1532 executes a child process, a sub routine, and the likeof the program executed by the main CPU 1531. The system controller 1533controls the operations of the main CPU 1531 and the sub CPU 1532 suchas designation of programs to be executed by the main CPU 1531 and thesub CPU 1532.

The display interface 1512 outputs the image data, for example, to theconnectivity 1321 (FIG. 42) or the like under the control of the controlunit 1511. For example, the display interface 1512 converts the imagedata that is digital data into an analog signal and outputs the imagedata to the monitoring device or the like of the connectivity 1321 (FIG.42) as a reproduced video signal or the image data that is the digitaldata.

The display engine 1513, under the control of the control unit 1511,performs various conversion processes such as a format conversion, asize conversion, and a color gamut conversion for the image data so asto be adjusted to the hardware specifications of the monitoring devicedisplaying the image or the like.

The image processing engine 1514, under the control of the control unit1511, performs predetermined image processing such as a filter processfor improving the image quality or the like for the image data.

The internal memory 1515 is a memory disposed inside the video processor1332 that is shared by the display engine 1513, the image processingengine 1514, and the codec engine 1516. The internal memory 1515, forexample, is used for data interchange performed among the display engine1513, the image processing engine 1514, and the codec engine 1516. Forexample, the internal memory 1515 stores data supplied from the displayengine 1513, the image processing engine 1514, or the codec engine 1516and supplies the data to the display engine 1513, the image processingengine 1514, or the codec engine 1516 as is necessary (for example, inaccordance with a request). While this internal memory 1515 may berealized by any storage device, generally, the internal memory 1515 isfrequently used for storing data having a small capacity such as imagedata configured in units of blocks or parameters, and accordingly, it ispreferably realized by a semiconductor memory having a relatively smallcapacity (for example, compared to the external memory 1312) and a highresponse speed such as a SRAM (Static Random Access Memory).

The codec engine 1516 performs the process relating to encoding ordecoding image data. The encoding/decoding system to which the codecengine 1516 corresponds is arbitrary, and the number thereof may be oneor two or more. For example, the codec engine 1516 may include a codecfunction of a plurality of encoding/decoding systems and perform theencoding of image data or the decoding of coded image data by usingselected one of the plurality of encoding/decoding systems.

In the example illustrated in FIG. 44, the codec engine 1516, forexample, includes MPEG-2 Video 1541, AVC/H.2641542, HEVC/H.2651543,HEVC/H.265 (Scalable) 1544, HEVC/H.265 (Multi-view) 1545, andMPEG-DASH1551 as functional blocks of the process relating to the codec.

The MPEG-2 Video1541 is a functional block used for encoding or decodingimage data in accordance with the MPEG-2 system. The AVC/H.264 1542 is afunctional block used for encoding or decoding image data in accordancewith the AVC system. In addition, the HEVC/H.265 1543 is a functionalblock used for encoding or decoding image data in accordance with theHEVC system. The HEVC/H.265 (Scalable) 1544 is a functional block usedfor scalable encoding or scalable decoding image data in accordance withthe HEVC system. The HEVC/H.265 (Multi-view) 1545 is a functional blockused for multiple viewpoint encoding or multiple viewpoint decodingimage data in accordance with the HEVC system.

The MPEG-DASH1551 is a functional block used for transmitting/receivingimage data in accordance with an MPEG-DASH (MPEG-Dynamic AdaptiveStreaming over HTTP) system. The MPEG-DASH is a technology for streaminga video by using an HTTP (HyperText Transfer Protocol) and has a featurethat one is appropriately selected from among a plurality of pieces ofcoded data having mutually-different resolutions and the like, which areprepared in advance, in units of segments and is transmitted. TheMPEG-DASH1551 performs generation of a stream, transmission control ofthe stream, and the like that are compliant with the specification, and,for encoding/decoding image data, uses MPEG-2 Video1541 or HEVC/H.265(Multi-view) 1545 described above.

The memory interface 1517 is an interface used for the external memory1312. Data supplied from the image processing engine 1514 or the codecengine 1516 is supplied to the external memory 1312 through the memoryinterface 1517. In addition, the data read from the external memory 1312is supplied to the video processor 1332 (the image processing engine1514 or the codec engine 1516) through the memory interface 1517.

The multiplexer/demultiplexer (MUX DMUX) 1518 multiplexes ordemultiplexes various kinds of data relating to an image such as abitstream of coded data, image data, or a video signal. Themultiplexing/demultiplexing method is arbitrary. For example, at thetime of the multiplexing process, the multiplexer/demultiplexer (MUXDMUX) 1518 may not only arrange a plurality of pieces of data into onebut also add predetermined header information or the like to the data.In addition, at the time of the demultiplexing process, themultiplexer/demultiplexer (MUX DMUX) 1518 may not only divide one pieceof data into a plurality of parts but also add predetermined headerinformation or the like to the divided data. In other words, themultiplexer/demultiplexer (MUX DMUX) 1518 can convert the format of datathrough a multiplexing/demultiplexing process. For example, themultiplexer/demultiplexer (MUX DMUX) 1518 can convert the bitstream intoa transport stream that is in the format for transmission or data (filedata) that is in the file format for recording by multiplexing the bitstream. It is apparent that the inverse conversion can be performedthrough a demultiplexing process.

The network interface 1519 is a dedicated interface such as thebroadband modem 1333 (FIG. 42) or the connectivity 1321 (FIG. 42). Thevideo interface 1520 is a dedicated interface such as the connectivity1321 (FIG. 42) or the camera 1322 (FIG. 42).

Next, an example of the operation of such a video processor 1332 will bedescribed. For example, when a transport stream is received from theexternal network through the connectivity 1321 (FIG. 42), the broadbandmodem 1333 (FIG. 42), or the like, the transport stream is supplied tothe multiplexer/demultiplexer (MUX DMUX) 1518 through the networkinterface 1519, is demultiplexed, and is decoded by the codec engine1516. For the image data acquired by the decoding process performed bythe codec engine 1516, for example, predetermined image processing isperformed by the image processing engine 1514, and predeterminedconversion is performed by the display engine 1513, the resultant imagedata is supplied, for example, to the connectivity 1321 (FIG. 42) or thelike through the display interface 1512, and the image is displayed onthe monitor. In addition, for example, the image data acquired by thedecoding process performed by the codec engine 1516 is re-coded by thecodec engine 1516, is multiplexed by the multiplexer/demultiplexer (MUXDMUX) 1518, is converted into file data, is output, for example, to theconnectivity 1321 (FIG. 42) or the like through the video interface1520, and is recorded on various recording media.

In addition, for example, file data of coded data that is acquired byencoding the image data read from a recording medium not illustrated inthe figure by the connectivity 1321 (FIG. 42) or the like is supplied tothe multiplexer/demultiplexer (MUX DMUX) 1518 through the videointerface 1520, is demultiplexed, and is decoded by the codec engine1516. The image data acquired by the decoding process performed by thecodec engine 1516 is subjected to predetermined image processingperformed by the image processing engine 1514, and a predeterminedconversion is performed by the display engine 1513, and the resultantimage data is supplied, for example, to the connectivity 1321 (FIG. 42)or the like through the display interface 1512, and the image isdisplayed on the monitor. Furthermore, for example, the image dataacquired by the decoding process performed by the codec engine 1516 isre-coded by the codec engine 1516, is multiplexed by themultiplexer/demultiplexer (MUX DMUX) 1518, is converted into a transportstream, is supplied, for example, to the connectivity 1321 (FIG. 42),the broadband modem 1333 (FIG. 42), or the like through the networkinterface 1519, and is transmitted to another device not illustrated inthe figure.

In addition, the interchange of image data or other data betweenprocessing units disposed within the video processor 1332, for example,is performed using the internal memory 1515 or the external memory 1312.In addition, the power management module 1313, for example, controls thesupply of power to the control unit 1511.

In a case where the present technology is applied to the video processor1332 configured as such, the present technology according to eachembodiment described above may be applied to the codec engine 1516. Inother words, for example, the codec engine 1516 may include a functionalblock that realizes the image encoding device 100 (FIG. 1) according tothe first embodiment or the image decoding device 200 (FIG. 19)according to the second embodiment. By configuring as such, the videoprocessor 1332 can acquire the same advantages as those described abovewith reference to FIGS. 1 to 31.

In addition, in the codec engine 1516, the present technology (in otherwords, the functions of the image encoding device and the image decodingdevice according to each embodiment described above) may be realized byhardware such as logic circuits, may be realized by software such as abuilt-in program, or may be realized by both the hardware and thesoftware.

As above, while two configurations of the video processor 1332 have beendescribed as examples, the configuration of the video processor 1332 isarbitrary and may be a configuration other than the two configurationsdescribed above. In addition, this video processor 1332 may beconfigured by either one semiconductor chip or a plurality ofsemiconductor chips. For example, the video processor 1332 may beconfigured by a three-dimensional laminated LSI in which a plurality ofsemiconductors is laminated. In addition, the video processor 1332 maybe realized by a plurality of LSI's.

[Example of Application to Device]

The video set 1300 may be built in various devices that process imagedata. For example, the video set 1300 may be built in the televisionapparatus 900 (FIG. 35), the mobile phone 920 (FIG. 36), the recordingand reproducing device 940 (FIG. 37), the imaging device 960 (FIG. 38),and the like. By building the video set 1300 therein, the devices canacquire advantages that are the same as those described above withreference to FIGS. 1 to 31.

In addition, the video set 1300, for example, may be built in theterminal devices of the data transmission system 1000 illustrated inFIG. 39 such as the personal computer 1004, the AV device 1005, thetablet device 1006, and the mobile phone 1007, the broadcasting station1101 and the terminal device 1102 of the data transmission system 1100illustrated in FIG. 40, and the imaging device 1201 and the scalablecoded data storage device 1202 of the imaging system 1200 illustrated inFIG. 41, and the like. By building the video set 1300 therein, thedevices can acquire advantages that are the same as the advantagesdescribed above with reference to FIGS. 1 to 31.

Furthermore, even if some of the configurations of the video set 1300described above may be configurations but the video processor 1332 isincluded, the configurations can be implemented as one in which thepresent technology is applied in a case. For example, only the videoprocessor 1332 may be configured as a video processor to which thepresent technology is applied. In addition, as described above, theprocessor, the video module 1311, and the like denoted by the dottedline 1341 may be configured as a processor, a module, and the like towhich the present technology is applied. Furthermore, for example, thevideo module 1311, the external memory 1312, the power management module1313, and the front end module 1314 may be combined so as to beconfigured as a video unit 1361 to which the present technology isapplied. In any of the configurations, the same advantages as thosedescribed above with reference to FIGS. 1 to 31 can be acquired.

In other words, any configuration that includes the video processor1332, similar to the case of the video set 1300, may be built in variousdevices that process image data. For example, the video processor 1332,the processor and the video module 1311 denoted by the dotted line 1341,or the video unit 1361 may be built in the television apparatus 900(FIG. 35), the mobile phone 920 (FIG. 36), the recording and reproducingdevice 940 (FIG. 37), the imaging device 960 (FIG. 38), the terminaldevices of the data transmission system 1000 illustrated in FIG. 39 suchas the personal computer 1004, the AV device 1005, the tablet device1006 and the mobile phone 1007, the broadcasting station 1101 and theterminal device 1102 of the data transmission system 1100 illustrated inFIG. 40, and the imaging device 1201 and the scalable coded data storagedevice 1202 of the imaging system 1200 illustrated in FIG. 41, and thelike. By building any configuration to which the present technology isapplied therein, similar to the case of the video set 1300, the devicescan acquire the same advantages as those described above with referenceto FIGS. 1 to 31.

Further, in the present specification, the examples have been describedin which various kinds of information such as skip enable information orskip identification information is multiplexed into a coded stream, andthe coded stream is transmitted from the coding side to the decodingside. However, the technique for transmitting the information is notlimited thereto. For example, the information may be transmitted orrecorded as separate data associated with a coded bit stream withoutbeing multiplexed into the coded bit stream. Here, the term “beingassociated” represents that an image (a slice, a block, or the like; itmay be a part of the image) included in a bit stream and informationcorresponding to the image are linked to each other at the time of thedecoding process. In other words, the information may be transmitted ona transmission line that is different from that of the image (or the bitstream). Furthermore, the information may be recorded on a recordingmedium (or a different storage area of the same recoding medium)different from the recoding medium of the image (or the bit stream). Inaddition, the information and the image (or the bit stream) may beassociated with each other in an arbitrary unit such as a plurality offrames, one frame, or a part of the frames.

The preferred embodiments of the present disclosure has been describedin detail with reference to the appended drawings, but the technicalscope of the present disclosure is not limited to the above examples. Itshould be understood by those skilled in the art that variousmodifications or alterations may occur within the scope of the technicalspirit described in claims and they are within the technical scope ofthe present invention.

The present technology can also have the following configurations:

(1) An image processing device including: a quantization unit that usesa weighting coefficient applied to an orthogonal transform skip block inwhich orthogonal transform processing is skipped and quantizes theorthogonal transform skip block; and an encoding unit that encodes acoefficient of the orthogonal transform skip block quantized by thequantization unit.

(2) The image processing device described in (1), wherein thequantization unit uses a spatial domain value as the weightingcoefficient.

(3) The image processing device described in (2), wherein thequantization unit uses one of the weighting coefficient.

(4) The image processing device described in (2), wherein thequantization unit uses a DC component of a quantization matrix used inquantizing an orthogonal transform block in which the orthogonaltransform processing is performed, as the weighting coefficient.

(5) The image processing device described in (2), wherein thequantization unit quantizes the orthogonal transform skip block using aweighting coefficient matrix obtained by performing matrix processing ona DC component of a quantization matrix.

(6) The image processing device described in (1), wherein thequantization unit quantizes the orthogonal transform skip block using aweighting coefficient matrix obtained by performing matrix processing onthe weighting coefficient.

(7) The image processing device described in (1), further including atransmission unit that transmits the weighting coefficient as a sequenceparameter set or a picture parameter set.

(8) The image processing device described in (1), further including atransmission unit that transmits skip enable information indicatingwhether or not to enable the skip of the orthogonal transform processingas a picture parameter set or as a slice header.

(9) The image processing device described in (8), wherein thetransmission unit transmits the skip enable information only when aminimum block size in performing an orthogonal transform is 4×4.

(10) The image processing device described in (1), further including atransmission unit that transmits the skip enable information as asequence parameter set only when a minimum block size in performing anorthogonal transform is 4×4.

(11) The image processing device described in (10), wherein thetransmission unit transmits the weighting coefficient subsequent to theskip enable information when the skip enable information is a value forenabling the skip of the orthogonal transform processing.

(12) An image processing method of an image processing device, whereinthe image processing device uses a weighting coefficient applied to anorthogonal transform skip block in which orthogonal transform processingis skipped, quantizes the orthogonal transform skip block, and encodes acoefficient of the quantized orthogonal transform skip block.

(13) An image processing device including: a filter unit that performs adeblocking filter on a locally decoded image when an image is subjectedto an encoding process; a control unit that controls the deblockingfilter by the filter unit so as to increase strength of the deblockingfilter with respect to a boundary between an orthogonal transform skipblock in which orthogonal transform processing is skipped and anorthogonal transform block in which the orthogonal transform isperformed; and an encoding unit that uses an image in which thedeblocking filter is performed by the filter unit and encodes the image.

(14) An image processing method of an image processing device, whereinthe image processing device performs a deblocking filter on a locallydecoded image when an image is subjected to an encoding process,controls the deblocking filter by the filter unit so as to increasestrength of the deblocking filter with respect to a boundary between anorthogonal transform skip block in which orthogonal transform processingis skipped and an orthogonal transform block in which the orthogonaltransform is performed, uses an image in which the deblocking filter isperformed by the filter unit, and encodes the image.

(15) An image processing device including: a decoding unit that performsa decoding process on a bit stream to generate an image; a filter unitthat performs a deblocking filter on the image generated by the decodingunit; and a control unit that controls the deblocking filter by thefilter unit so as to increase strength of the deblocking filter withrespect to a boundary between an orthogonal transform skip block inwhich orthogonal transform processing is skipped and an orthogonaltransform block in which the orthogonal transform is performed.

(16) An image processing method of an image processing device, whereinthe image processing device performs a decoding process on a bit streamto generate an image, performs a deblocking filter on the generatedimage, and controls the deblocking filter so as to increase strength ofthe deblocking filter with respect to a boundary between an orthogonaltransform skip block in which orthogonal transform processing is skippedand an orthogonal transform block in which the orthogonal transform isperformed.

(21) An image processing device including:

a quantization unit that uses a weighting coefficient applied to anorthogonal transform skip block in which orthogonal transform processingis skipped and quantizes the orthogonal transform skip block; and

an encoding unit that encodes a coefficient of the orthogonal transformskip block quantized by the quantization unit.

(22) The image processing device according to (21), wherein thequantization unit uses the one weighting coefficient.

(23) The image processing device according to (22), wherein thequantization unit quantizes an orthogonal transform skip block having ablock size of 4×4 using the weighting coefficient.

(24) The image processing device according to (23), further including atransmission unit that transmits skip enable information indicatingwhether or not to enable the skip of the orthogonal transform processingas a picture parameter set.

(25) The image processing device according to (24), wherein thetransmission unit further transmits the weighting coefficient.

(26) The image processing device according to (21), wherein thequantization unit quantizes a non-orthogonal transform skip block inwhich orthogonal transform processing is performed, using a quantizationmatrix different from a weighting coefficient matrix obtained byperforming matrix processing on the weighting coefficient.

(27) The image processing device according to (24), further including atransmission unit that modulates coded data obtained by performingquantization by the quantization unit and encoding by the encoding unitimage data to transmit the coded data as a transmission signal.

(28) The image processing device according to (24), further including amultiplexer that multiplexes coded data obtained by performingquantization by the quantization unit and encoding by the encoding unitimage data, with audio coded data.

(29) The image processing device according to (24), further including animaging unit that captures an image of an object to generate image data,

wherein the quantization unit quantizes the orthogonal transform skipblock of the image data obtained by imaging with the imaging unit.

(30) The image processing device according to (24), further including anaudio codec unit that performs encoding and decoding on audio data.

(31) The image processing device according to (24), further including arecording unit that records coded data obtained by performingquantization by the quantization unit and encoding by the encoding unitimage data, on a storage medium

(32) An image processing method including:

using a weighting coefficient applied to an orthogonal transform skipblock in which orthogonal transform processing is skipped to quantizethe orthogonal transform skip block; and

encoding a coefficient of the quantized orthogonal transform skip block.

REFERENCE SIGNS LIST

-   100 Image encoding device-   104 Orthogonal transform unit-   105 Quantization unit-   106 Lossless encoding unit-   108 Inverse quantization unit-   109 Inverse orthogonal transform unit-   111 Deblocking filter-   121 Orthogonal transform skip unit-   131 Skip encoding unit-   132 Skip determination unit-   141 Quantization matrix setting unit-   142 Weighting coefficient generation unit-   143 Quantization processing unit-   151 Boundary determination unit-   152 Strength adjustment unit-   153 Filtering unit-   200 Image decoding device-   202 Lossless decoding unit-   203 Inverse quantization unit-   204 Inverse orthogonal transform unit-   206 Deblocking filter-   221 Inverse orthogonal transform skip unit-   231 TransformSkipFlag buffer-   232 Control signal generation unit-   241 Quantization matrix buffer-   242 Weighting coefficient generation unit-   243 Quantization parameter buffer-   244 Inverse quantization unit-   251 Boundary determination unit-   252 Strength adjustment unit-   253 Filtering unit

1-12. (canceled)
 13. An image processing device comprising: aquantization unit that quantizes an orthogonal transform skip block, inwhich orthogonal transform processing is skipped, using a quantizationmatrix made up of one coefficient; and an encoding unit that encodes acoefficient of the orthogonal transform skip block quantized by thequantization unit.
 14. The image processing device according to claim13, wherein the quantization matrix is 4×4.
 15. The image processingdevice according to claim 13, wherein the quantization unit quantizes anorthogonal transform skip block having a block size of 4×4 using theweighting coefficient.
 16. The image processing device according toclaim 13, further comprising a transmission unit that transmits skipenable information indicating whether or not to enable the skip of theorthogonal transform processing as a picture parameter set.
 17. Theimage processing device according to claim 13, wherein the quantizationunit quantizes a non-orthogonal transform skip block in which orthogonaltransform processing is performed, using a quantization matrix differentfrom the quantization matrix.
 18. The image processing device accordingto claim 13, further comprising a transmission unit that modulates codeddata obtained by performing quantization by the quantization unit andencoding by the encoding unit image data to transmit the coded data as atransmission signal.
 19. The image processing device according to claim13, further comprising a multiplexer that multiplexes coded dataobtained by performing quantization by the quantization unit andencoding by the encoding unit image data, with audio coded data.
 20. Theimage processing device according to claim 13, further comprising animaging unit that captures an image of an object to generate image data,wherein the quantization unit quantizes the orthogonal transform skipblock of the image data obtained by imaging with the imaging unit. 21.The image processing device according to claim 13, further comprising anaudio codec unit that performs encoding and decoding on audio data. 22.The image processing device according to claim 13, further comprising arecording unit that records coded data obtained by performingquantization by the quantization unit and encoding by the encoding unitimage data, on a storage medium.
 23. An image processing methodcomprising: quantizing an orthogonal transform skip block, in whichorthogonal transform processing is skipped, using a quantization matrixmade up of one coefficient; and encoding a coefficient of the quantizedorthogonal transform skip block.